for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> BIOLOGY (Total: 2982 journals)
    - BIOCHEMISTRY (231 journals)
    - BIOENGINEERING (105 journals)
    - BIOLOGY (1420 journals)
    - BIOPHYSICS (46 journals)
    - BIOTECHNOLOGY (217 journals)
    - BOTANY (219 journals)
    - CYTOLOGY AND HISTOLOGY (28 journals)
    - ENTOMOLOGY (63 journals)
    - GENETICS (162 journals)
    - MICROBIOLOGY (254 journals)
    - MICROSCOPY (10 journals)
    - ORNITHOLOGY (25 journals)
    - PHYSIOLOGY (69 journals)
    - ZOOLOGY (133 journals)

BIOLOGY (1420 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 1720 Journals sorted alphabetically
AAPS Journal     Hybrid Journal   (Followers: 18)
Achievements in the Life Sciences     Open Access   (Followers: 4)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 20)
Acta Biologica Colombiana     Open Access   (Followers: 6)
Acta Biologica Hungarica     Full-text available via subscription   (Followers: 4)
Acta Biologica Sibirica     Open Access  
Acta Biomaterialia     Hybrid Journal   (Followers: 25)
Acta Biotheoretica     Hybrid Journal   (Followers: 5)
Acta Chiropterologica     Full-text available via subscription   (Followers: 6)
acta ethologica     Hybrid Journal   (Followers: 4)
Acta Limnologica Brasiliensia     Open Access   (Followers: 3)
Acta Médica Costarricense     Open Access   (Followers: 2)
Acta Musei Silesiae, Scientiae Naturales : The Journal of Silesian Museum in Opava     Open Access  
Acta Parasitologica     Hybrid Journal   (Followers: 9)
Acta Scientiarum. Biological Sciences     Open Access   (Followers: 2)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
Actualidades Biológicas     Open Access   (Followers: 1)
Advanced Health Care Technologies     Open Access   (Followers: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Bioinformatics     Open Access   (Followers: 18)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4)
Advances in Biology     Open Access   (Followers: 8)
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 6)
Advances in Cell Biology     Open Access   (Followers: 23)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Ecological Research     Full-text available via subscription   (Followers: 39)
Advances in Ecology     Open Access   (Followers: 13)
Advances in Environmental Sciences - International Journal of the Bioflux Society     Open Access   (Followers: 20)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Genome Biology     Full-text available via subscription   (Followers: 12)
Advances in High Energy Physics     Open Access   (Followers: 20)
Advances in Human Biology     Open Access  
Advances in Life Science and Technology     Open Access   (Followers: 14)
Advances in Life Sciences     Open Access   (Followers: 4)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 21)
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3)
Advances in Regenerative Biology     Open Access   (Followers: 1)
Advances in Structural Biology     Full-text available via subscription   (Followers: 7)
Advances in Virus Research     Full-text available via subscription   (Followers: 5)
African Journal of Range & Forage Science     Hybrid Journal   (Followers: 6)
AFRREV STECH : An International Journal of Science and Technology     Open Access   (Followers: 1)
Ageing Research Reviews     Hybrid Journal   (Followers: 7)
Aging Cell     Open Access   (Followers: 9)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat     Open Access  
AJP Cell Physiology     Full-text available via subscription   (Followers: 13)
AJP Endocrinology and Metabolism     Full-text available via subscription   (Followers: 22)
AJP Lung Cellular and Molecular Physiology     Full-text available via subscription   (Followers: 3)
Al-Kauniyah : Jurnal Biologi     Open Access  
Alasbimn Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Biology Teacher     Full-text available via subscription   (Followers: 12)
American Fern Journal     Full-text available via subscription   (Followers: 1)
American Journal of Agricultural and Biological Sciences     Open Access   (Followers: 10)
American Journal of Bioethics     Hybrid Journal   (Followers: 10)
American Journal of Biostatistics     Open Access   (Followers: 9)
American Journal of Human Biology     Hybrid Journal   (Followers: 12)
American Journal of Medical and Biological Research     Open Access   (Followers: 5)
American Journal of Plant Sciences     Open Access   (Followers: 19)
American Journal of Primatology     Hybrid Journal   (Followers: 14)
American Malacological Bulletin     Full-text available via subscription   (Followers: 3)
American Naturalist     Full-text available via subscription   (Followers: 63)
Amphibia-Reptilia     Hybrid Journal   (Followers: 6)
Anaerobe     Hybrid Journal   (Followers: 4)
Analytical Methods     Full-text available via subscription   (Followers: 7)
Anatomical Science International     Hybrid Journal   (Followers: 2)
Animal Cells and Systems     Hybrid Journal   (Followers: 4)
Annales de Limnologie - International Journal of Limnology     Hybrid Journal   (Followers: 1)
Annales françaises d'Oto-rhino-laryngologie et de Pathologie Cervico-faciale     Full-text available via subscription   (Followers: 3)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3)
Annales UMCS, Biologia     Open Access   (Followers: 1)
Annals of Applied Biology     Hybrid Journal   (Followers: 8)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 18)
Annals of Human Biology     Hybrid Journal   (Followers: 4)
Annual Review of Biomedical Engineering     Full-text available via subscription   (Followers: 17)
Annual Review of Biophysics     Full-text available via subscription   (Followers: 25)
Annual Review of Cell and Developmental Biology     Full-text available via subscription   (Followers: 37)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 14)
Annual Review of Genomics and Human Genetics     Full-text available via subscription   (Followers: 18)
Annual Review of Phytopathology     Full-text available via subscription   (Followers: 10)
Anthropological Review     Open Access   (Followers: 23)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antibiotics     Open Access   (Followers: 8)
Antioxidants     Open Access   (Followers: 4)
Antioxidants & Redox Signaling     Hybrid Journal   (Followers: 8)
Antonie van Leeuwenhoek     Hybrid Journal   (Followers: 5)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apidologie     Hybrid Journal   (Followers: 4)
Apmis     Hybrid Journal   (Followers: 1)
APOPTOSIS     Hybrid Journal   (Followers: 8)
Applied Bionics and Biomechanics     Open Access   (Followers: 8)
Applied Vegetation Science     Full-text available via subscription   (Followers: 9)
Aquaculture Environment Interactions     Open Access   (Followers: 2)
Aquaculture International     Hybrid Journal   (Followers: 22)
Aquaculture Reports     Open Access   (Followers: 3)
Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society     Open Access   (Followers: 6)
Aquatic Biology     Open Access   (Followers: 4)
Aquatic Ecology     Hybrid Journal   (Followers: 30)
Aquatic Ecosystem Health & Management     Hybrid Journal   (Followers: 13)
Aquatic Science and Technology     Open Access   (Followers: 3)
Aquatic Toxicology     Hybrid Journal   (Followers: 19)
Archaea     Open Access   (Followers: 3)
Archiv für Molluskenkunde: International Journal of Malacology     Full-text available via subscription   (Followers: 3)
Archives of Biomedical Sciences     Open Access   (Followers: 7)
Archives of Microbiology     Hybrid Journal   (Followers: 8)
Archives of Natural History     Hybrid Journal   (Followers: 7)
Archives of Oral Biology     Hybrid Journal   (Followers: 2)
Archives of Virology     Hybrid Journal   (Followers: 5)
Archivum Immunologiae et Therapiae Experimentalis     Hybrid Journal   (Followers: 2)
Arid Ecosystems     Hybrid Journal   (Followers: 3)
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Arquivos do Museu Dinâmico Interdisciplinar     Open Access  
Arthropod Structure & Development     Hybrid Journal   (Followers: 2)
Arthropods     Open Access   (Followers: 1)
Artificial DNA: PNA & XNA     Hybrid Journal   (Followers: 2)
Artificial Photosynthesis     Open Access   (Followers: 1)
Asian Bioethics Review     Full-text available via subscription   (Followers: 1)
Asian Journal of Biodiversity     Open Access   (Followers: 5)
Asian Journal of Biological Sciences     Open Access   (Followers: 3)
Asian Journal of Cell Biology     Open Access   (Followers: 5)
Asian Journal of Developmental Biology     Open Access   (Followers: 2)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 2)
Asian Journal of Nematology     Open Access   (Followers: 3)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Australian Life Scientist     Full-text available via subscription   (Followers: 2)
Australian Mammalogy     Hybrid Journal   (Followers: 5)
Autophagy     Hybrid Journal   (Followers: 2)
Avian Biology Research     Full-text available via subscription   (Followers: 3)
Avian Conservation and Ecology     Open Access   (Followers: 7)
Bacteriology Journal     Open Access   (Followers: 2)
Bacteriophage     Full-text available via subscription   (Followers: 3)
Bangladesh Journal of Bioethics     Open Access  
Bangladesh Journal of Plant Taxonomy     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Berita Biologi     Open Access   (Followers: 1)
Between the Species     Open Access   (Followers: 1)
Bio Tribune Magazine     Hybrid Journal  
BIO Web of Conferences     Open Access  
BIO-Complexity     Open Access  
Bio-Grafía. Escritos sobre la Biología y su enseñanza     Open Access  
Bioanalytical Reviews     Hybrid Journal   (Followers: 2)
Biocatalysis and Biotransformation     Hybrid Journal   (Followers: 6)
Biochemistry and Cell Biology     Full-text available via subscription   (Followers: 14)
Biochimie     Hybrid Journal   (Followers: 7)
BioControl     Hybrid Journal   (Followers: 5)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 5)
Biodemography and Social Biology     Hybrid Journal   (Followers: 1)
Biodiversidad Colombia     Open Access  
Biodiversity : Research and Conservation     Open Access   (Followers: 26)
Biodiversity and Natural History     Open Access   (Followers: 5)
Biodiversity Data Journal     Open Access   (Followers: 3)
Biodiversity Informatics     Open Access  
Bioedukasi : Jurnal Pendidikan Biologi FKIP UM Metro     Open Access  
Bioeksperimen : Jurnal Penelitian Biologi     Open Access  
Bioelectrochemistry     Hybrid Journal   (Followers: 2)
Bioelectromagnetics     Hybrid Journal   (Followers: 1)
Bioenergy Research     Hybrid Journal   (Followers: 2)
Bioengineering and Bioscience     Open Access   (Followers: 1)
BioEssays     Hybrid Journal   (Followers: 10)
Bioethics     Hybrid Journal   (Followers: 14)
BioéthiqueOnline     Open Access  
Biofabrication     Hybrid Journal   (Followers: 3)
Biogeosciences (BG)     Open Access   (Followers: 9)
Biogeosciences Discussions (BGD)     Open Access   (Followers: 1)
Bioinformatics     Hybrid Journal   (Followers: 232)
Bioinformatics and Biology Insights     Open Access   (Followers: 14)
Bioinspiration & Biomimetics     Hybrid Journal   (Followers: 6)
Biointerphases     Open Access   (Followers: 1)
Biojournal of Science and Technology     Open Access  
Biologia     Hybrid Journal  
Biologia on-line : Revista de divulgació de la Facultat de Biologia     Open Access  
Biological Bulletin     Partially Free   (Followers: 4)
Biological Control     Hybrid Journal   (Followers: 5)
Biological Invasions     Hybrid Journal   (Followers: 16)
Biological Journal of the Linnean Society     Hybrid Journal   (Followers: 14)
Biological Letters     Open Access   (Followers: 4)
Biological Procedures Online     Open Access  
Biological Psychiatry     Hybrid Journal   (Followers: 41)
Biological Psychology     Hybrid Journal   (Followers: 6)
Biological Research     Open Access  
Biological Rhythm Research     Hybrid Journal   (Followers: 2)
Biological Theory     Hybrid Journal   (Followers: 1)
Biological Trace Element Research     Hybrid Journal  
Biologicals     Full-text available via subscription   (Followers: 9)
Biologics: Targets & Therapy     Open Access   (Followers: 1)
Biologie Aujourd'hui     Full-text available via subscription  
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 44)
Biologija     Open Access  
Biology     Open Access   (Followers: 5)
Biology and Philosophy     Hybrid Journal   (Followers: 16)
Biology Bulletin     Hybrid Journal   (Followers: 1)
Biology Bulletin Reviews     Hybrid Journal  
Biology Direct     Open Access   (Followers: 7)
Biology Letters     Full-text available via subscription   (Followers: 35)
Biology Methods and Protocols     Hybrid Journal  

        1 2 3 4 5 6 7 8 | Last

Journal Cover Arthropod Structure & Development
  [SJR: 0.983]   [H-I: 45]   [2 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1467-8039
   Published by Elsevier Homepage  [3031 journals]
  • Segmentation in Tardigrada and diversification of segmental patterns in
           Panarthropoda
    • Authors: Frank W. Smith; Bob Goldstein
      Pages: 328 - 340
      Abstract: Publication date: May 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 3
      Author(s): Frank W. Smith, Bob Goldstein
      The origin and diversification of segmented metazoan body plans has fascinated biologists for over a century. The superphylum Panarthropoda includes three phyla of segmented animals—Euarthropoda, Onychophora, and Tardigrada. This superphylum includes representatives with relatively simple and representatives with relatively complex segmented body plans. At one extreme of this continuum, euarthropods exhibit an incredible diversity of serially homologous segments. Furthermore, distinct tagmosis patterns are exhibited by different classes of euarthropods. At the other extreme, all tardigrades share a simple segmented body plan that consists of a head and four leg-bearing segments. The modular body plans of panarthropods make them a tractable model for understanding diversification of animal body plans more generally. Here we review results of recent morphological and developmental studies of tardigrade segmentation. These results complement investigations of segmentation processes in other panarthropods and paleontological studies to illuminate the earliest steps in the evolution of panarthropod body plans.

      PubDate: 2017-05-22T17:11:37Z
      DOI: 10.1016/j.asd.2016.10.005
       
  • Segmentation and tagmosis in Chelicerata
    • Authors: Jason A. Dunlop; James C. Lamsdell
      Pages: 395 - 418
      Abstract: Publication date: May 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 3
      Author(s): Jason A. Dunlop, James C. Lamsdell
      Patterns of segmentation and tagmosis are reviewed for Chelicerata. Depending on the outgroup, chelicerate origins are either among taxa with an anterior tagma of six somites, or taxa in which the appendages of somite I became increasingly raptorial. All Chelicerata have appendage I as a chelate or clasp-knife chelicera. The basic trend has obviously been to consolidate food-gathering and walking limbs as a prosoma and respiratory appendages on the opisthosoma. However, the boundary of the prosoma is debatable in that some taxa have functionally incorporated somite VII and/or its appendages into the prosoma. Euchelicerata can be defined on having plate-like opisthosomal appendages, further modified within Arachnida. Total somite counts for Chelicerata range from a maximum of nineteen in groups like Scorpiones and the extinct Eurypterida down to seven in modern Pycnogonida. Mites may also show reduced somite counts, but reconstructing segmentation in these animals remains challenging. Several innovations relating to tagmosis or the appendages borne on particular somites are summarised here as putative apomorphies of individual higher taxa. We also present our observations within the concept of pseudotagma, whereby the true tagmata – the prosoma and opisthosoma – can be defined on a fundamental change in the limb series while pseudotagmata, such as the cephalosoma/proterosoma, are expressed as divisions in sclerites covering the body without an accompanying change in the appendages.

      PubDate: 2017-05-22T17:11:37Z
      DOI: 10.1016/j.asd.2016.05.002
       
  • Editorial
    • Authors: Alexander Steinbrecht; Nicholas Strausfeld
      First page: 1
      Abstract: Publication date: January 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 1
      Author(s): Alexander Steinbrecht, Nicholas Strausfeld


      PubDate: 2017-02-05T14:12:04Z
      DOI: 10.1016/j.asd.2017.01.003
       
  • The arthropod cuticle – A never-ending endeavor
    • Authors: Helge-Otto Fabritius; Bernard Moussian
      Pages: 2 - 3
      Abstract: Publication date: January 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 1
      Author(s): Helge-Otto Fabritius, Bernard Moussian


      PubDate: 2017-02-05T14:12:04Z
      DOI: 10.1016/j.asd.2017.01.004
       
  • Mineral in skeletal elements of the terrestrial crustacean Porcellio
           scaber: SRμCT of function related distribution and changes during the
           moult cycle
    • Authors: Andreas Ziegler; Frank Neues; Jiří Janáček; Felix Beckmann; Matthias Epple
      Pages: 63 - 76
      Abstract: Publication date: January 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 1
      Author(s): Andreas Ziegler, Frank Neues, Jiří Janáček, Felix Beckmann, Matthias Epple
      Terrestrial isopods moult first the posterior and then the anterior half of the body, allowing for storage and recycling of CaCO3. We used synchrotron-radiation microtomography to estimate mineral content within skeletal segments in sequential moulting stages of Porcellio scaber. The results suggest that all examined cuticular segments contribute to storage and recycling, however, to varying extents. The mineral within the hepatopancreas after moult suggests an uptake of mineral from the ingested exuviae. The total maximum loss of mineral was 46% for the anterior and 43% for the posterior cuticle. The time course of resorption of mineral and mineralisation of the new cuticle suggests storage and recycling of mineral in the posterior and anterior cuticle. The mineral in the anterior pereiopods decreases by 25% only. P. scaber has long legs and can run fast; therefore, a less mineralised and thus lightweight cuticle in pereiopods likely serves to lower energy consumption during escape behaviour. Differential demineralisation occurs in the head cuticle, in which the cornea of the complex eyes remains completely mineralised. The partes incisivae of the mandibles are mineralised before the old cuticle is demineralised and shed. Probably, this enables the animal to ingest the old exuviae after each half moult.
      Graphical abstract image

      PubDate: 2017-02-05T14:12:04Z
      DOI: 10.1016/j.asd.2016.05.004
       
  • Testicular, spermatogenesis and sperm morphology in Martarega bentoi
           (Heteroptera: Notonectidae)
    • Authors: Ademária M. Novais; Glenda Dias; José Lino-Neto
      Abstract: Publication date: Available online 18 May 2017
      Source:Arthropod Structure & Development
      Author(s): Ademária M. Novais, Glenda Dias, José Lino-Neto
      The testicular, spermatogenesis and sperm morphology of the backswimmer Martarega bentoi was described using light and transmission electron microscopy. In this species, a pair of testes, two deferent ducts, two different pairs of accessory glands, and an ejaculatory duct form the male reproductive system. Each testis consists of two testicular follicles, which are arranged side by side in snail shape. The follicles are filled with cysts at different stages of spermatogenesis, but in the same cyst the germ cells (up to 64) are in the same stage. At the end of spermatogenesis, the sperm cells are very long, with the flagellum measuring approximately 2500 μm in length, the nucleus only 19 μm, and the acrosome, with two distinct regions, 300 μm. The flagellum is composed of an axoneme, with a 9 + 9 + 2 microtubular pattern, and 2 asymmetric mitochondrial derivatives (MDs). These have the anterior ends inserted into two cavities at the nucleus base, exhibit two paracrystalline inclusions, and have bridges linking them to the axoneme. Few spermatozoa per cyst, asymmetry in size and shape of the MDs, as well as their insertion at the nuclear base are characteristics considered derived, and that differentiate the sperm of M. bentoi from those of the Nepomorpha, Belostomatidae and Nepidae.

      PubDate: 2017-05-22T17:11:37Z
      DOI: 10.1016/j.asd.2017.04.002
       
  • Advisory board/short GFA
    • Abstract: Publication date: May 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 3


      PubDate: 2017-05-22T17:11:37Z
       
  • Ultrastructure of spermiogenesis and spermatozoa in Marchalina hellenica
           (Gennadius) (Hemiptera: Sternorrhyncha, Marchalinidae)
    • Authors: Romano Dallai; David Mercati; Sofia Gounari; Francesco Paoli; Pietro Lupetti
      Abstract: Publication date: Available online 24 April 2017
      Source:Arthropod Structure & Development
      Author(s): Romano Dallai, David Mercati, Sofia Gounari, Francesco Paoli, Pietro Lupetti
      The spermiogenesis, the sperm structure and the sperm motility of Marchalina hellenica (Gennadius) were examined. In the early spermiogenesis a centriolar apparatus was identified, but this structure is not involved in the production of the sperm flagellum. As in other Coccoidea, the flagellar axoneme originates by the activity of the thickened tip of the numerous microtubules surrounding the nuclear anterior region close to the periphery of the cell. This region pushes against a narrow cytoplasmic layer, giving rise to a papilla. In this region a novel structure, consisting of a regular network of thin filaments, arranged orthogonally to the bundle of microtubules, is visible. The sperm flagellum consists of a series of about 260 microtubules, regularly arranged in rings around the axial nucleus. This latter extends in the middle part of the sperm length. As usual in scale insects, sperm form a bundle, which in M. hellenica is composed of 64 sperm cells, surrounded by somatic cyst cells. The sperm bundle has an helicoidal array, with a cap of dense material at its apex, lending the anterior and the posterior region of the sperm bundle with a different structural organization. This difference is responsible of the different speed gradient observed in the helical wave propagating along the sperm bundle.

      PubDate: 2017-04-26T15:28:16Z
      DOI: 10.1016/j.asd.2017.03.004
       
  • The thoracic morphology of the wingless dune cricket Comicus calcaris
           (Orthoptera: Schizodactylidae): Novel apomorphic characters for the group
           and adaptations to sand desert environments
    • Authors: Fanny Leubner; Sven Bradler; Benjamin Wipfler
      Abstract: Publication date: Available online 21 April 2017
      Source:Arthropod Structure & Development
      Author(s): Fanny Leubner, Sven Bradler, Benjamin Wipfler
      Schizodactylidae, splay-footed or dune crickets, represents a distinct lineage among the highly diverse orthopteran subgroup Ensifera (crickets, katydids and allies). Only two extant genera belong to the Schizodactylidae: the winged Eurasian genus Schizodactylus, whose ecology and morphology is well documented, and the wingless South African Comicus, for which hardly any studies providing morphological descriptions have been conducted since its taxonomic description in 1888. Based on the first in-depth study of the skeletomuscular system of the thorax of Comicus calcaris Irish 1986, we provide information on some unique characteristics of this character complex in Schizodactylidae. They include a rigid connection of prospinasternite and mesosternum, a T-shaped mesospina, and a fused meso- and metasternum. Although Schizodactylidae is mainly characterized by group-specific anatomical traits of the thorax, its bifurcated profuca supports a closer relationship to the tettigonioid ensiferans, like katydids, wetas, and hump-winged crickets. Some specific features of the thoracic musculature of Comicus seem to be correlated to the skeletal morphology, e.g., due to the rigid connection of the tergites and pleurites in the pterothorax not a single direct flight muscle is developed. We show that many of the thoracic adaptations in these insects are directly related to their psammophilous way of life. These include a characteristic setation of thoracic sclerites that prevent sand grains from intrusion into vulnerable membranous areas, the striking decrease in size of the thoracic spiracles that reduces the respirational water loss, and a general trend towards a fusion of sclerites in the thorax.
      Graphical abstract image

      PubDate: 2017-04-26T15:28:16Z
      DOI: 10.1016/j.asd.2017.03.006
       
  • Comparative morphology of the prothoracic leg in heliconian butterflies:
           Tracing size allometry, podite fusions and losses in ontogeny and
           phylogeny
    • Authors: Gilson R.P. Moreira; Denis S. Silva; Gislene L. Gonçalves
      Abstract: Publication date: Available online 20 April 2017
      Source:Arthropod Structure & Development
      Author(s): Gilson R.P. Moreira, Denis S. Silva, Gislene L. Gonçalves
      Prothoracic legs of heliconian butterflies (Nymphalidae, Heliconiinae, Heliconiini) are reduced in size compared to mesothoracic and metathoracic legs. They have no apparent function in males, but are used by females for drumming on host plants, a behavior related to oviposition site selection. Here, taking into account all recognized lineages of heliconian butterflies, we described their tarsi using optical and scanning electron microscopy and searched for podite fusions and losses, and analyzed allometry at the static, ontogenetic and phylogenetic levels. Female tarsi were similar, club-shaped, showing from four to five tarsomeres, each bearing sensilla chaetica and trichodea. Male tarsi were cylindrical, formed from five (early diverging lineages) to one (descendant lineages) either partially or totally fused tarsomeres, all deprived of sensilla. Pretarsi were reduced in both sexes, in some species being either vestigial or absent. Tarsal lengths were smaller for males in almost all species. An abrupt decrease in size was detected for the prothoracic legs during molting to the last larval instar at both histological and morphometric levels. In both sexes, most allometric coefficients found at the population level for the prothoracic legs were negative compared to the mesothoracic leg and also to wings. Prothoracic tarsi decreased proportionally in size over evolutionary time; the largest and smallest values being found for nodes of the oldest and youngest lineages, respectively. Our results demonstrate that evolution of the prothoracic leg in heliconian butterflies has been based on losses and fusions of podites, in association with negative size allometry at static, ontogenetic and phylogenetic levels. These processes have been more pronounced in males. Our study provided further support to the hypothesis that evolution of these leg structures is driven by females, by changing their use from walking to drumming during oviposition site selection. In males the leg would have been selected against due to absence of function and thus progressively reduced in size, in association with podites fusions and lost.

      PubDate: 2017-04-26T15:28:16Z
      DOI: 10.1016/j.asd.2017.03.008
       
  • No sight, no smell? – Brain anatomy of two amphipod crustaceans
           with different lifestyles
    • Authors: Till Ramm; Gerhard Scholtz
      Abstract: Publication date: Available online 20 April 2017
      Source:Arthropod Structure & Development
      Author(s): Till Ramm, Gerhard Scholtz
      The brain anatomy of Niphargus puteanus and Orchestia cavimana, two amphipod species with different lifestyles, has been studied using a variety of recent techniques. The general aspects of the brain anatomy of both species correspond to those of other malacostracans. However, both species lack hemiellipsoid bodies. Furthermore, related to their lifestyle certain differences have been observed. The aquatic subterranean species N. puteanus lacks eye structures, the optic nerve, and the two outer optic neuropils lamina and medulla. Only partial remains of the lobula have been detected. In contrast to this, the central complex in the protocerebrum and the olfactory glomeruli in the deutocerebrum are well differentiated. The terrestrial species Orchestia cavimana shows a reduced first antenna, the absence of olfactory neuropils in the deutocerebrum, and a reduction of the olfactory globular tract. The characteristics in defining the hemiellipsoid bodies are critically discussed. Contradictions about presence or absence of this neuropil are due to different conceptualizations. A comparison with other crustaceans that live in dark environments reveal similar patterns of optic system reduction, but to different degrees following a centripetal pattern. Retaining the olfactory system seems a general problem of terrestrialization in crustaceans with the notable exception of terrestrial hermit crabs.
      Graphical abstract image

      PubDate: 2017-04-26T15:28:16Z
      DOI: 10.1016/j.asd.2017.03.003
       
  • The sensory arrays of the ant, Temnothorax rugatulus
    • Authors: Fiorella Ramirez-Esquivel; Nicole E. Leitner; Jochen Zeil; Ajay Narendra
      Abstract: Publication date: Available online 12 April 2017
      Source:Arthropod Structure & Development
      Author(s): Fiorella Ramirez-Esquivel, Nicole E. Leitner, Jochen Zeil, Ajay Narendra
      Individual differences in response thresholds to task-related stimuli may be one mechanism driving task allocation among social insect workers. These differences may arise at various stages in the nervous system. We investigate variability in the peripheral nervous system as a simple mechanism that can introduce inter-individual differences in sensory information. In this study we describe size-dependent variation of the compound eyes and the antennae in the ant Temnothorax rugatulus. Head width in T. rugatulus varies between 0.4 and 0.7 mm (2.6–3.8 mm body length). But despite this limited range of worker sizes we find sensory array variability. We find that the number of ommatidia and of some, but not all, antennal sensilla types vary with head width. The antennal array of T. rugatulus displays the full complement of sensillum types observed in other species of ants, although at much lower quantities than other, larger, studied species. In addition, we describe what we believe to be a new type of sensillum in hymenoptera that occurs on the antennae and on all body segments. T. rugatulus has apposition compound eyes with 45–76 facets per eye, depending on head width, with average lens diameters of 16.5 μm, rhabdom diameters of 5.7 μm and inter-ommatidial angles of 16.8°. The optical system of T. rugatulus ommatidia is severely under focussed, but the absolute sensitivity of the eyes is unusually high. We discuss the functional significance of these findings and the extent to which the variability of sensory arrays may correlate with task allocation.

      PubDate: 2017-04-19T14:52:03Z
      DOI: 10.1016/j.asd.2017.03.005
       
  • Mantisbot is a robotic model of visually guided motion in the praying
           mantis
    • Authors: Nicholas S. Szczecinski; Andrew P. Getsy; Joshua P. Martin; Roy E. Ritzmann; Roger D. Quinn
      Abstract: Publication date: Available online 28 March 2017
      Source:Arthropod Structure & Development
      Author(s): Nicholas S. Szczecinski, Andrew P. Getsy, Joshua P. Martin, Roy E. Ritzmann, Roger D. Quinn
      Insects use highly distributed nervous systems to process exteroception from head sensors, compare that information with state-based goals, and direct posture or locomotion toward those goals. To study how descending commands from brain centers produce coordinated, goal-directed motion in distributed nervous systems, we have constructed a conductance-based neural system for our robot MantisBot, a 29 degree-of-freedom, 13.3:1 scale praying mantis robot. Using the literature on mantis prey tracking and insect locomotion, we designed a hierarchical, distributed neural controller that establishes the goal, coordinates different joints, and executes prey-tracking motion. In our controller, brain networks perceive the location of prey and predict its future location, store this location in memory, and formulate descending commands for ballistic saccades like those seen in the animal. The descending commands are simple, indicating only 1) whether the robot should walk or stand still, and 2) the intended direction of motion. Each joint's controller uses the descending commands differently to alter sensory-motor interactions, changing the sensory pathways that coordinate the joints' central pattern generators into one cohesive motion. Experiments with one leg of MantisBot show that visual input produces simple descending commands that alter walking kinematics, change the walking direction in a predictable manner, enact reflex reversals when necessary, and can control both static posture and locomotion with the same network.

      PubDate: 2017-03-28T13:51:22Z
      DOI: 10.1016/j.asd.2017.03.001
       
  • Sperm ultrastructure of shrimp from family Penaeidae (Crustacea:
           Dendrobranchiata) in a phylogenetic context
    • Authors: Tavani Rocha Camargo; Natalia Rossi; Antonio L. Castilho; Rogério C. Costa; Fernando L. Mantelatto; Fernando José Zara
      Abstract: Publication date: Available online 27 March 2017
      Source:Arthropod Structure & Development
      Author(s): Tavani Rocha Camargo, Natalia Rossi, Antonio L. Castilho, Rogério C. Costa, Fernando L. Mantelatto, Fernando José Zara
      We describe the sperm ultrastructure of six penaeid species, including at least one member of each tribe (Penaeini, Parapenaeini and Trachypenaeini). Fragments of the vas deferens of the Penaeidae Farfantepenaeus brasiliensis, Farfantepenaeus paulensis, Litopenaeus schmitti, Parapenaeus americanus, Rimapenaeus constrictus and Xiphopenaeus kroyeri were fixed and processed according to the routine for transmission electron microscopy. The morphological results were contextualized in an evolutionary perspective using molecular markers for the phylogenetic reconstruction of this group. A phylogram was proposed by Bayesian inference based on 1007 bp of 33 sequences of the combined genes (16S rDNA and COI mtDNA) from 27 dendrobranchiate specimens. Our findings show that morphological differences in the sperm ultrastructures of members among the tribes of Penaeidae can be used as a baseline to understand their evolutionary relationships. Individuals from the Penaeini tribe show plesiomorphic characteristics in the sperm ultrastructure compared to the Trachypenaeini tribe from which they were derived, such as shrimp from family Sicyoniidae. The morphological complexity of the sperm of the different penaeid members corroborated with the genetic phylogeny, which showed different clades for each tribe and the close relationship with Sicyoniidae. The sperm features of the selected species studied here reflected their evolutionary history. These features confirm the previous phylogenetic hypothesis and question the monophyly of Penaeidae, which should be verified in the future with a more complete set of representative members of each tribe.

      PubDate: 2017-03-28T13:51:22Z
      DOI: 10.1016/j.asd.2017.01.006
       
  • Introduction: The evolution of segmentation
    • Authors: Alessandro Minelli
      Abstract: Publication date: Available online 23 March 2017
      Source:Arthropod Structure & Development
      Author(s): Alessandro Minelli


      PubDate: 2017-03-28T13:51:22Z
      DOI: 10.1016/j.asd.2017.02.002
       
  • Development and evolution of segmentation assessed by geometric
           morphometrics: The centipede Strigamia maritima as a case study
    • Authors: Yoland Savriama; Sylvain Gerber; Matteo Baiocco; Vincent Debat; Giuseppe Fusco
      Abstract: Publication date: Available online 22 March 2017
      Source:Arthropod Structure & Development
      Author(s): Yoland Savriama, Sylvain Gerber, Matteo Baiocco, Vincent Debat, Giuseppe Fusco
      Using the centipede model species Strigamia maritima as a subject of study, we illustrate the potential of geometric morphometrics for investigating the development and evolution of segmentation, with a specific focus on post-embryonic segmental patterning. We show how these techniques can contribute detailed descriptive data for comparative purposes, but also precious information on some features of the developmental system that are considered relevant for the evolvability of a segmented body architecture, such as developmental stability and canalization. Morphometric analyses allow to separately investigate several sources of phenotypic variation along a segmented body axis, like constitutive and random segment heteronomy, both within and among individuals. Specifically, in S. maritima, the segmental pattern of ventral sclerite shapes mirrors that of their bilateral fluctuating asymmetry and among-individual variation in associating the most anterior and most posterior segments in diverging from the central ones. Also, among segments, there seems to be a correlation between fluctuating asymmetry and shape variation among individuals, suggesting that canalization and developmental stability are somehow associated. Overall, these associations might stem from a joint influence of the segmental position on the two processes of developmental buffering.
      Graphical abstract image

      PubDate: 2017-03-28T13:51:22Z
      DOI: 10.1016/j.asd.2017.03.002
       
  • Using insects to drive mobile robots — hybrid robots bridge the gap
           between biological and artificial systems
    • Authors: Noriyasu Ando; Ryohei Kanzaki
      Abstract: Publication date: Available online 18 March 2017
      Source:Arthropod Structure & Development
      Author(s): Noriyasu Ando, Ryohei Kanzaki
      The use of mobile robots is an effective method of validating sensory–motor models of animals in a real environment. The well-identified insect sensory–motor systems have been the major targets for modeling. Furthermore, mobile robots implemented with such insect models attract engineers who aim to avail advantages from organisms. However, directly comparing the robots with real insects is still difficult, even if we successfully model the biological systems, because of the physical differences between them. We developed a hybrid robot to bridge the gap. This hybrid robot is an insect-controlled robot, in which a tethered male silkmoth (Bombyx mori) drives the robot in order to localize an odor source. This robot has the following three advantages: 1) from a biomimetic perspective, the robot enables us to evaluate the potential performance of future insect-mimetic robots; 2) from a biological perspective, the robot enables us to manipulate the closed-loop of an onboard insect for further understanding of its sensory–motor system; and 3) the robot enables comparison with insect models as a reference biological system. In this paper, we review the recent works regarding insect-controlled robots and discuss the significance for both engineering and biology.
      Graphical abstract image

      PubDate: 2017-03-21T13:14:18Z
      DOI: 10.1016/j.asd.2017.02.003
       
  • Stylet biogenesis in Bactericera cockerelli (Hemiptera: Triozidae)
    • Authors: Joseph M. Cicero
      Abstract: Publication date: Available online 18 March 2017
      Source:Arthropod Structure & Development
      Author(s): Joseph M. Cicero
      The discovery of ‘Ca. Liberibacter solanacearum’, causal agent of certain solanaceous and apiaceous crop diseases, inside the functional (intrastadial) and pharate stylet anatomy of the potato psyllid prompted elucidation of the mechanism of stylet replacement as a novel exit portal in the transmission pathway. In Hemiptera, presumptive (formative) stylets, secreted during consecutive pharate instars, replace functional stylets lost with the exuviae. In potato psyllids, each functional stylet has a hollow core filled with a cytology that extends out of the core to form a hemispherical aggregate of cells, the ‘end-cap’, somewhat resembling a golf ball on a tee. A tightly folded mass of extremely thin cells, the ‘matrix’, occurs inside the end-cap. Micrograph interpretations indicate that during the pharate stage, the end-cap apolyses from the core and ‘deconstructs’ to release and expand the matrix into a long, coiled tube, the ‘atrium’. Cells that were in contact with the inner walls of the functional stylet core maintain their position at the apex of the tube, and secrete a new stylet, apex first, the growing length of which descends into the tube until completed. They then despool from the coils into their functional position as the exuviae is shed.
      Graphical abstract image

      PubDate: 2017-03-21T13:14:18Z
      DOI: 10.1016/j.asd.2016.12.007
       
  • Advisory board/short GFA
    • Abstract: Publication date: March 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 2


      PubDate: 2017-03-21T13:14:18Z
       
  • Formation of the acrosome complex in the bush cricket Gampsocleis gratiosa
           (Orthoptera: Tettigoniidae)
    • Authors: Cai Xia Su; Jie Chen; Fu Ming Shi; Ming Shen Guo; Yan Lin Chang
      Abstract: Publication date: Available online 3 March 2017
      Source:Arthropod Structure & Development
      Author(s): Cai Xia Su, Jie Chen, Fu Ming Shi, Ming Shen Guo, Yan Lin Chang
      The acrosome complex plays an indispensable role in the normal function of mature spermatozoa. However, the dynamic process of acrosome complex formation in insect remains poorly understood. Gampsocleis gratiosa Brunner von Wattenwyl possesses the typical characteristic of insect sperms, which is tractable in terms of size, and therefore was selected for the acrosome formation study in this report. The results show that acrosome formation can be divided into six phases: round, rotating, rhombic, cylindrical, transforming and mature phase, based on the morphological dynamics of acrosome complex and nucleus. In addition, the cytoskeleton plays a critical role in the process of acrosome formation. The results from this study indicate that: (1) glycoprotein is the major component of the acrosome proper; (2) the microfilament is one element of the acrosome complex, and may mediate the morphologic change of the acrosome complex; (3) the microtubules might also shape the nucleus and acrosome complex during the acrosome formation.

      PubDate: 2017-03-03T22:41:27Z
      DOI: 10.1016/j.asd.2017.01.002
       
  • The morphology and ultrastructure of salivary glands of Zoraptera
           (Insecta)
    • Authors: R. Dallai; D. Mercati; Y. Mashimo; R. Machida; R.G. Beutel
      Abstract: Publication date: Available online 2 March 2017
      Source:Arthropod Structure & Development
      Author(s): R. Dallai, D. Mercati, Y. Mashimo, R. Machida, R.G. Beutel
      The salivary glands of two species of Zoraptera, Zorotypus caudelli and Zorotypus hubbardi, were examined and documented mainly using transmission electron microscopy (TEM). The results obtained for males and females of the two species are compared and functional aspects related to ultrastructural features are discussed. The salivary glands are divided into two regions: the secretory cell region and the long efferent duct, the latter with its distal end opening in the salivarium below the hypopharyngeal base. The secretory region consists of a complex of secretory cells provided with microvillated cavities connected by short ectodermal ducts to large ones, which are connected with the long efferent duct. The secretory cell cytoplasm contains a large system of rough endoplasmic reticulum and Golgi apparatus producing numerous dense secretions. The cells of the efferent duct, characterized by reduced cytoplasm and the presence of long membrane infoldings associated with mitochondria, are possibly involved in fluid uptaking from the duct lumen.

      PubDate: 2017-03-03T22:41:27Z
      DOI: 10.1016/j.asd.2017.02.001
       
  • Haltere morphology and campaniform sensilla arrangement across Diptera
    • Authors: Sweta Agrawal; David Grimaldi; Jessica L. Fox
      Abstract: Publication date: Available online 23 February 2017
      Source:Arthropod Structure & Development
      Author(s): Sweta Agrawal, David Grimaldi, Jessica L. Fox
      One of the primary specializations of true flies (order Diptera) is the modification of the hind wings into club-shaped halteres. Halteres are complex mechanosensory structures that provide sensory feedback essential for stable flight control via an array of campaniform sensilla at the haltere base. The morphology of these sensilla has previously been described in a small number of dipteran species, but little is known about how they vary across fly taxa. Using a synoptic set of specimens representing 42 families from all of the major infraorders of Diptera, we used scanning electron microscopy to map the gross and fine structures of halteres, including sensillum shape and arrangement. We found that several features of haltere morphology correspond with dipteran phylogeny: Schizophora generally have smaller halteres with stereotyped and highly organized sensilla compared to nematoceran flies. We also found a previously undocumented high variation of haltere sensillum shape in nematoceran dipterans, as well as the absence of a dorsal sensillum field in multiple families. Overall, variation in haltere sensillar morphology across the dipteran phylogeny provides insight into the evolution of a highly specialized proprioceptive organ and a basis for future studies on haltere sensory function.

      PubDate: 2017-02-24T20:56:12Z
      DOI: 10.1016/j.asd.2017.01.005
       
  • Linking gene regulation to cell behaviors in the posterior growth zone of
           sequentially segmenting arthropods
    • Authors: Terri A. Williams; Lisa M. Nagy
      Abstract: Publication date: Available online 15 February 2017
      Source:Arthropod Structure & Development
      Author(s): Terri A. Williams, Lisa M. Nagy
      Virtually all arthropods all arthropods add their body segments sequentially, one by one in an anterior to posterior progression. That process requires not only segment specification but typically growth and elongation. Here we review the functions of some of the key genes that regulate segmentation: Wnt, caudal, Notch pathway, and pair-rule genes, and discuss what can be inferred about their evolution. We focus on how these regulatory factors are integrated with growth and elongation and discuss the importance and challenges of baseline measures of growth and elongation. We emphasize a perspective that integrates the genetic regulation of segment patterning with the cellular mechanisms of growth and elongation.

      PubDate: 2017-02-17T17:14:07Z
      DOI: 10.1016/j.asd.2016.10.003
       
  • A molecular view of onychophoran segmentation
    • Authors: Ralf Janssen
      Abstract: Publication date: Available online 15 February 2017
      Source:Arthropod Structure & Development
      Author(s): Ralf Janssen
      This paper summarizes our current knowledge on the expression and assumed function of Drosophila and (other) arthropod segmentation gene orthologs in Onychophora, a closely related outgroup to Arthropoda. This includes orthologs of the so-called Drosophila segmentation gene cascade including the Hox genes, as well as other genetic factors and pathways involved in non-drosophilid arthropods. Open questions about and around the topic are addressed, such as the definition of segments in onychophorans, the unclear regulation of conserved expression patterns downstream of non-conserved factors, and the potential role of mesodermal patterning in onychophoran segmentation.

      PubDate: 2017-02-17T17:14:07Z
      DOI: 10.1016/j.asd.2016.10.004
       
  • Fine structure of the anterior median eyes of the funnel-web spider
           Agelena labyrinthica (Araneae: Agelenidae)
    • Authors: Wolfgang-D. Schröer
      Abstract: Publication date: Available online 10 February 2017
      Source:Arthropod Structure & Development
      Author(s): Wolfgang-D. Schröer
      Only few electron microscopic studies exist on the structure of the main eyes (anterior median eyes, AME) of web spiders. The present paper provides details on the anatomy of the AME in the funnel-web spider Agelena labyrinthica. The retina consists of two separate regions with differently arranged photoreceptor cells. Its central part has sensory cells with rhabdomeres on 2, 3, or 4 sides, whereas those of the ventral retina have only two rhabdomeres on opposite sides. In addition, the rhabdomeres of the ventral retina are arranged in a specific way: Whereas in the most ventral part they form long tangential rows, those towards the center are detached and are arranged radially. All sensory cells are wrapped by unpigmented pigment cell processes. In agelenid spiders the axons of the sensory cells exit from the middle of the cell body; their fine structure and course through the eye cup is described in detail. In the central part of the retina efferent nerve fibres were found forming synapses along the distal region of the receptor cells. A muscle is attached laterally to each eye cup that allows mainly rotational movements of the eyes. The optical performance (image resolution) of these main eyes with relatively few visual cells is discussed.

      PubDate: 2017-02-12T18:18:15Z
      DOI: 10.1016/j.asd.2017.01.001
       
  • Muscular system in interna of Peltogaster paguri (Rhizocephala:
           Peltogastridae)
    • Authors: Aleksei A. Miroliubov
      Abstract: Publication date: Available online 9 February 2017
      Source:Arthropod Structure & Development
      Author(s): Aleksei A. Miroliubov
      Rhizocephalan parasites have a peculiar life cycle, and their adults lost almost all traits found usually in Crustacea. Despite some data on anatomy and ultrastructure of interna of Peltogastridae, some crucial aspects of morphology are still unknown. For example, there is only one mentioning of myocytes found in interna of Rhizocephalans (Sacculina carcini). So we aimed at studying the muscular system of the interna of Peltogaster paguri using serial histological sectioning and fluorescent staining (TRITC-labeled phalloidin) with confocal microscopy. Within the wall of the main trunk we found striated muscular fibers. The majority of these fibers form a unidirectional single spiral. There are additional small fibers that connect the coils of the large spiral. The density of muscular fibers is highest near the externa stalk, and the number of muscle fibers decreases towards the distal part of the main trunk. We suggest that such a muscular system could provide peristaltic movements of the main trunk and the transport of nutrients through the interna.

      PubDate: 2017-02-12T18:18:15Z
      DOI: 10.1016/j.asd.2016.11.005
       
  • Comparative study of the morphology of the female seminal receptacles of
           Ilia nucleus and Persephona mediterranea (Decapoda, Brachyura,
           Leucosiidae)
    • Authors: Sarah Hayer; Stephanie Köhnk; Christoph D. Schubart; Susann Boretius; Stanislav N. Gorb; Dirk Brandis
      Abstract: Publication date: Available online 8 February 2017
      Source:Arthropod Structure & Development
      Author(s): Sarah Hayer, Stephanie Köhnk, Christoph D. Schubart, Susann Boretius, Stanislav N. Gorb, Dirk Brandis
      Because of the poor knowledge of the morphology of the female reproductive organs of most brachyuran crabs, this study investigated two Atlantic representatives of the family Leucosiidae, Ilia nucleus (Linnaeus, 1758) and Persephona mediterranea (Herbst, 1794), using histological methods and magnetic resonance imaging (MRI). While the vagina conforms to the concave type, the arrangement of the two chambers of the seminal receptacle differs strongly from that of other eubrachyuran sperm storage organs. Both chambers are oriented laterally within the crab's body. This is in contrast to the dorso-ventral orientation described in most other known brachyuran crabs. The lateral chamber is covered by cuticle, whereas the medial chamber is covered by a holocrine glandular epithelium. The oviduct connection is located ventrally, posterior to the vagina. The oviduct orifice is characterized by a transition from the epithelium lining the oviduct to the seminal receptacle's holocrine glandular epithelium. Moreover, muscle fibres are attached to the oviduct orifice and to the sternal cuticle. This musculature can be interpreted as an important feature in the fertilization and egg-laying process by supporting and controlling the inflow of eggs into the seminal receptacle lumen. The results of this study are compared to the morphology of the seminal receptacle of another leucosiid crab, Ebalia tumefacta (Montagu, 1808), and to those of other known eubrachyuran crabs.

      PubDate: 2017-02-12T18:18:15Z
      DOI: 10.1016/j.asd.2016.12.006
       
  • Head anatomy of adult Coniopteryx pygmaea Enderlein, 1906: Effects of
           miniaturization and the systematic position of Coniopterygidae (Insecta:
           Neuroptera)
    • Authors: Susanne Randolf; Dominique Zimmermann; Ulrike Aspöck
      Abstract: Publication date: Available online 6 February 2017
      Source:Arthropod Structure & Development
      Author(s): Susanne Randolf, Dominique Zimmermann, Ulrike Aspöck
      External and internal head structures of adult Coniopteryx pygmaea Enderlein, 1906, one of the smallest known lacewings, are described in detail for the first time. Possible effects of miniaturization and two hypotheses on the phylogenetic position of Coniopterygidae are evaluated and compared with data from literature. Several convergent modifications in C. pygmaea and other miniaturized insect species are outlined, e.g., a relative increase in the size of the brain, simplification of the tracheal system with respect to the number of tracheae, and reduction of the number of ommatidia and diameter of the facets. Further, the ocular ridge is bell-shaped and countersunk into the head capsule. The cuticle is weakly sclerotized and equipped with wax glands which are unique in Neuroptera. The total number of muscles is not affected by miniaturization. The phylogenetic analysis yields Coniopterygidae as sistergroup to the dilarid clade based on one larval character, the shape of the stylets. The enforced basal position of Coniopterygidae is supported by one disputable synapomorphy of the remaining Neuroptera, the presence of paraglossae in adults.

      PubDate: 2017-02-12T18:18:15Z
      DOI: 10.1016/j.asd.2016.12.004
       
  • Ontogenetic trajectory and allometry of Diplonychus rusticus (Fabricius),
           an Oriental aquatic bug (Hemiptera: Belostomatidae) from the Western Ghats
           of India
    • Authors: Dnyaneshwar Doke; Rashmi Morey; Neelesh Dahanukar; Sameer M. Padhye; Shruti V. Paripatyadar
      Abstract: Publication date: Available online 28 January 2017
      Source:Arthropod Structure & Development
      Author(s): Dnyaneshwar Doke, Rashmi Morey, Neelesh Dahanukar, Sameer M. Padhye, Shruti V. Paripatyadar
      Despite being one of the dominant groups in freshwater ecosystems, morphological and ontogenetic studies on aquatic Hemiptera have received little attention in the Oriental region. We present the ontogenetic trajectory and allometry of the widespread Oriental belostomatid species, Diplonychus rusticus (Fabricius) for the first time. We have measured nine different morphological variables throughout the growth of the bug using both field captured and laboratory reared specimens. Our results suggest that the developmental instars can be distinguished by the size variables, as seen in the Principal Component Analysis. On the basis of a CHAID (Chi-squared Automatic Interaction Detection) based regression tree, we also show that the characters – total length without head and maximum width – prove to be adequate for effective instar identification. The multivariate allometric growth pattern shows that different body parts exhibit different types of allometry. This is apparent in the allometry exhibited by forelegs and mid and hind legs, which show allometry of opposite polarities. This may be due to the different functions attributed to these body parts. Our results show that the growth pattern in D. rusticus is comparable with the New World genus Belostoma, suggesting a conserved growth pattern in the family Belostomatidae.

      PubDate: 2017-01-29T13:25:32Z
      DOI: 10.1016/j.asd.2016.12.008
       
  • Ultrastructure of chemoreceptive tarsal sensilla in an armored harvestman
           and evidence of olfaction across Laniatores (Arachnida, Opiliones)
    • Authors: Guilherme Gainett; Peter Michalik; Carsten H.G. Müller; Gonzalo Giribet; Giovanni Talarico; Rodrigo H. Willemart
      Abstract: Publication date: Available online 10 January 2017
      Source:Arthropod Structure & Development
      Author(s): Guilherme Gainett, Peter Michalik, Carsten H.G. Müller, Gonzalo Giribet, Giovanni Talarico, Rodrigo H. Willemart
      Harvestmen (Arachnida, Opiliones) are especially dependent on chemical cues and are often regarded as animals that rely mainly on contact chemoreception. Information on harvestman sensilla is scarce when compared to other arachnid orders, especially concerning internal morphology. Using scanning (SEM) and transmission (TEM) electron microscopy, we investigated tarsal sensilla on the distal tarsomeres (DT) of all leg pairs in Heteromitobates discolor (Laniatores, Gonyleptidae). Furthermore, we explored the typological diversity of sensilla present on the DT I and II in members of the suborder Laniatores, which include two thirds of the formally described opilionid fauna, using species from 17 families representing all main laniatorian lineages. Our data revealed that DT I and II of H. discolor are equipped with wall-pored falciform hairs (two types), wall-pored sensilla chaetica (two types) and tip-pored sensilla chaetica, while DT III and IV are mainly covered with trichomes (non-sensory) and tip-pored sensilla chaetica. The ultrastructural characteristics support an olfactory function for all wall-pored sensilla and a dual gustatory/mechanoreceptive function for tip-pored sensilla chaetica. Based on our comparative SEM survey, we show that wall-pored sensilla occur in all investigated Laniatores, demonstrating their widespread occurrence in the suborder and highlighting the importance of both legs I and II as the sensory appendages of laniatorean harvestmen. Our results provide the first morphological evidence for olfactory receptors in Laniatores and suggest that olfaction is more important for harvestmen than previously thought.
      Graphical abstract image

      PubDate: 2017-01-15T11:14:27Z
      DOI: 10.1016/j.asd.2016.12.005
       
  • Structure and postembryonic development of the intersegmental nodules in
           the non-muscular joints of the antennae in Rhodnius prolixus
    • Authors: Bibiana Ospina-Rozo; Manu Forero-Shelton; Jorge Molina
      Abstract: Publication date: Available online 6 January 2017
      Source:Arthropod Structure & Development
      Author(s): Bibiana Ospina-Rozo, Manu Forero-Shelton, Jorge Molina
      The antennae of Insecta consist of two basal segments and the distal annulated flagellum lacking intrinsic muscles. Non-muscular joints are important to preserve the flexibility and structure of the long heteropteran antennae which bear an intersegmental nodule on each non-muscular joint. Little is known about their properties or function. Here we characterize the structure and postembryonic development of the non-muscular joints of Rhodnius prolixus antennae. Using Scanning Electron Microscopy, we tracked the changes in shape and size of both intersegmental nodules during the course of the hemimetabolous insect life cycle. Using Atomic Force Microscopy, we established a qualitative correlation between the topography of the surface and the rigidity of the joint between pedicel and flagellum. Our results confirmed the presence of two sub-articulations on each non-muscular joint. Also, the two intersegmental nodules have different origins: the one between the two flagellar segments (intraflagelloid) is a sclerite already present from the early nymph, while the nodule between pedicel and flagellum (prebasiflagellite) originates by gradual separation of the proximal end of the basiflagellum during postembryonic development. Various changes occur in the non-muscular joints and segments of the antenna during the life cycle of R. prolixus.
      Graphical abstract image

      PubDate: 2017-01-08T10:38:54Z
      DOI: 10.1016/j.asd.2016.12.002
       
  • The length of a short sperm: Elongation and shortening during
           spermiogenesis in Cotesia congregata (Hymenoptera, Braconidae)
    • Authors: Rustem Uzbekov; Julien Burlaud-Gaillard; Anastasiia S. Garanina; Christophe Bressac
      Abstract: Publication date: Available online 5 January 2017
      Source:Arthropod Structure & Development
      Author(s): Rustem Uzbekov, Julien Burlaud-Gaillard, Anastasiia S. Garanina, Christophe Bressac
      The spermatozoon of the parasitoid wasp Cotesia congregata is an extremely short gamete measuring less than 7 μm; it is as yet the shortest flagellated sperm to be identified. The mature sperm consists of an acrosome, surrounded by an extra cellular coat, a condensed nucleus, two uncoiled mitochondrial derivatives and a short axoneme. Testes of young adults contain a continuum of differentiation stages. Initially, the flagellum is approximately 5 μm long. It conserves its length in round, elongated and mature spermatids, but is reduced to less than 3 μm in mature spermatozoa. The nucleus is 2 μm in diameter when round, 10 μm long when it becomes a long boat-hull shaped filament, and then reduces to 3.6 μm. Thus, during development the gamete reaches a total length of 15 μm before finally reducing to less than half that length. Some traits of mature sperm anatomy are similar to related species of the Braconidae family, but others seem to be specific and could be due to the shortness of the cell. This uncommon elongation and subsequent shortening of such a tiny flagellated cell constitutes a model for both nucleus and cilium development.
      Graphical abstract image

      PubDate: 2017-01-08T10:38:54Z
      DOI: 10.1016/j.asd.2016.11.011
       
  • Germ cell proliferation and cluster behavior in ovarioles of Sialis
           flavilatera (Megaloptera: Sialidae) during larval growth
    • Authors: Ralph
      Abstract: Publication date: Available online 4 January 2017
      Source:Arthropod Structure & Development
      Author(s): Ralph Rübsam, Jürgen Büning
      Telotrophic meroistic insect ovaries are assigned to four different types. The Sialis type is found in Sialidae (Megaloptera), Raphidioptera and a coleopteran subgroup (Myxophaga: Hydroscaphidae). King and Büning (1985) proposed a hypothetical model for the development of this ovariole type; however, a detailed description of ovarian development in Sialis was missing so far. Using light and electron microscopy, we investigated developing ovaries of Sialis flavilatera starting in the 10th month of the biennial larval phase until adulthood. At least from the 10th month onwards, a Sialis ovariole anlage contains a single germ cell syncytium, whose growth is promoted by a mitotic cell population maintained in its anterior compartment. The stem-like, dividing germ cells form synchronous sub-clusters consisting of 2–16 cystocytes, which are spatially arranged in bigger rosettes that stay connected to each other via cytoplasmic tubes. Within individual rosettes, cells communicate by centrally gathering intercellular bridges. Following each round of cystocyte division and subsequent rosette formation, plasma membrane wrinkles sprout near newborn bridges, elongate, and interdigitate with the preexisting membrane tubes. In this way the membrane labyrinth emerges and grows. Germ cells leaving the proliferation zone posteriorly enter meiotic prophase. Hypotheses on the phylogenetic origin of this ovary type are discussed in the light of our results.

      PubDate: 2017-01-08T10:38:54Z
       
  • The scolopidial accessory organ in the Jerusalem cricket (Orthoptera:
           Stenopelmatidae)
    • Authors: Johannes
      Abstract: Publication date: Available online 4 January 2017
      Source:Arthropod Structure & Development
      Author(s): Johannes Strauß
      Multiple mechanosensory organs form the subgenual organ complex in orthopteroid insects, located in the proximal tibia. In several Ensifera (Orthoptera), a small chordotonal organ, the so-called accessory organ, is the most posterior part of this sensory complex. In order to document the presence of this accessory organ among the Ensifera, the chordotonal sensilla and their innervation in the posterior tibia of two species of Jerusalem crickets (Stenopelmatidae: Stenopelmatus) is described. The sensory structures were stained by axonal tracing. Scolopidial sensilla occur in the posterior subgenual organ and the accessory organ in all leg pairs. The accessory organ contains 10–17 scolopidial sensilla. Both groups of sensilla are commonly spatially separated. However, in few cases neuronal fibres occurred between both organs. The two sensillum groups are considered as separate organs by the general spatial separation and innervation by different nerve branches. A functional role for mechanoreception is considered: since the accessory organ is located closely under the cuticle, sensilla may be suited to detect vibrations transferred over the leg's surface. This study extends the known taxa with an accessory organ, which occurs in several taxa of Ensifera. Comparative neuroanatomy thus suggests that the accessory organ may be conserved at least in Tettigoniidea.
      Graphical abstract image

      PubDate: 2017-01-08T10:38:54Z
       
  • Cuticular body hairs mediate clumping of small Camponotus floridanus
           larvae
    • Authors: Yiwen Wang; Renata Zuber; Annette Laudahn; Jürgen Berger; Bernard Moussian
      Abstract: Publication date: Available online 3 January 2017
      Source:Arthropod Structure & Development
      Author(s): Yiwen Wang, Renata Zuber, Annette Laudahn, Jürgen Berger, Bernard Moussian
      The body surface of insects usually carries cuticular hairs. Commonly, important functions of these structures are to prevent drowning and to defend against predators. Here, we report on our studies on hairs at the surface of larvae of the ant species Camponotus floridanus and Camponotus sericeiventris. First, we present data supporting the hypothesis that anti-drowning properties of the surface might rely on cuticular hairs. Second, we show that especially in young larvae body hairs serve as attachment and interlocking devices mediating clumping of larvae facilitating transport by workers. Based on our observations, we speculate that clumping also enhances larval perceptibility. Taken together, larval cuticular hairs seem to have at least two important functions augmenting chances of larval survival. Obviously, despite their immobility, young Camponotus larvae support childcare in the ant colony providing an arsenal of cuticular hairs on their body surface.

      PubDate: 2017-01-08T10:38:54Z
      DOI: 10.1016/j.asd.2016.12.003
       
  • Patterns of inner chorion structure in Anastrepha (Diptera: Tephritidae)
           eggs
    • Authors: Julia V.A. Figueiredo; André L.P. Perondini; Denise Selivon
      Abstract: Publication date: Available online 22 December 2016
      Source:Arthropod Structure & Development
      Author(s): Julia V.A. Figueiredo, André L.P. Perondini, Denise Selivon
      The inner chorion structure of Anastrepha eggs from 16 species of various infrageneric taxonomic groups is described by scanning and transmission electron microscopy. The layers of the chorion, the outer egg membrane, are structurally similar. Furthermore, an additional trabecular layer (ATL) that exists in some species, together with other characteristics, facilitates the recognition of four patterns of chorion structuring: Pattern I, in which the ATL layer is absent, is found in Anastrepha amita, the Anastrepha fraterculus complex, Anastrepha obliqua, Anastrepha sororcula, Anastrepha suspensa and Anastrepha zenildae (fraterculus group), and Anastrepha bistrigata and Anastrepha striata (striata group); Pattern II in Anastrepha serpentina (serpentina group), Anastrepha grandis (grandis group) and Anastrepha pseudoparallela (pseudoparallela group), in which the ATL presents large open spaces with pillars; Pattern III, found in Anastrepha consobrina (pseudoparallela group), in which the ATL is composed of round cavities; and Pattern IV, found in Anastrepha alveata and Anastrepha pickeli (spatulata group), where the large ATL cavities are reticulated. Comparatively, the chorion structure in Anastrepha eggs is more complex than in eggs of other fruit flies, e.g., Bactrocera, Rhagoletis and Ceratitis.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.004
       
  • Patterns of inner chorion structure in Anastrepha (Diptera: Tephritidae)
           eggs
    • Authors: Julia V.A. Figueiredo; André L.P. Perondini; Denise Selivon
      Abstract: Publication date: Available online 22 December 2016
      Source:Arthropod Structure & Development
      Author(s): Julia V.A. Figueiredo, André L.P. Perondini, Denise Selivon
      The inner chorion structure of Anastrepha eggs from 16 species of various infrageneric taxonomic groups is described by scanning and transmission electron microscopy. The layers of the chorion, the outer egg membrane, are structurally similar. Furthermore, an additional trabecular layer (ATL) that exists in some species, together with other characteristics, facilitates the recognition of four patterns of chorion structuring: Pattern I, in which the ATL layer is absent, is found in Anastrepha amita, the Anastrepha fraterculus complex, Anastrepha obliqua, Anastrepha sororcula, Anastrepha suspensa and Anastrepha zenildae (fraterculus group), and Anastrepha bistrigata and Anastrepha striata (striata group); Pattern II in Anastrepha serpentina (serpentina group), Anastrepha grandis (grandis group) and Anastrepha pseudoparallela (pseudoparallela group), in which the ATL presents large open spaces with pillars; Pattern III, found in Anastrepha consobrina (pseudoparallela group), in which the ATL is composed of round cavities; and Pattern IV, found in Anastrepha alveata and Anastrepha pickeli (spatulata group), where the large ATL cavities are reticulated. Comparatively, the chorion structure in Anastrepha eggs is more complex than in eggs of other fruit flies, e.g., Bactrocera, Rhagoletis and Ceratitis.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.004
       
  • Patterns of inner chorion structure in Anastrepha (Diptera: Tephritidae)
           eggs
    • Authors: Julia V.A. Figueiredo; André L.P. Perondini; Denise Selivon
      Abstract: Publication date: Available online 22 December 2016
      Source:Arthropod Structure & Development
      Author(s): Julia V.A. Figueiredo, André L.P. Perondini, Denise Selivon
      The inner chorion structure of Anastrepha eggs from 16 species of various infrageneric taxonomic groups is described by scanning and transmission electron microscopy. The layers of the chorion, the outer egg membrane, are structurally similar. Furthermore, an additional trabecular layer (ATL) that exists in some species, together with other characteristics, facilitates the recognition of four patterns of chorion structuring: Pattern I, in which the ATL layer is absent, is found in Anastrepha amita, the Anastrepha fraterculus complex, Anastrepha obliqua, Anastrepha sororcula, Anastrepha suspensa and Anastrepha zenildae (fraterculus group), and Anastrepha bistrigata and Anastrepha striata (striata group); Pattern II in Anastrepha serpentina (serpentina group), Anastrepha grandis (grandis group) and Anastrepha pseudoparallela (pseudoparallela group), in which the ATL presents large open spaces with pillars; Pattern III, found in Anastrepha consobrina (pseudoparallela group), in which the ATL is composed of round cavities; and Pattern IV, found in Anastrepha alveata and Anastrepha pickeli (spatulata group), where the large ATL cavities are reticulated. Comparatively, the chorion structure in Anastrepha eggs is more complex than in eggs of other fruit flies, e.g., Bactrocera, Rhagoletis and Ceratitis.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.004
       
  • Autofluorescence lifetime variation in the cuticle of the bedbug Cimex
           lectularius
    • Authors: Klaus Reinhardt; Hans Georg Breunig; Karsten König
      Abstract: Publication date: Available online 22 December 2016
      Source:Arthropod Structure & Development
      Author(s): Klaus Reinhardt, Hans Georg Breunig, Karsten König
      The decay time of the fluorescence of excited molecules, called fluorescence lifetime, can provide information about the cuticle composition additionally to widely used spectral characteristics. We compared autofluorescence lifetimes of different cuticle regions in the copulatory organ of females of the bedbug, Cimex lectularius. After two-photon excitation at 720 nm, regions recently characterised as being rich in resilin showed a longer bimodal distribution of the mean autofluorescence lifetime τm (tau-m) at 0.4 ns and 1.0–1.5 ns, while resilin-poor sites exhibited a unimodal pattern with a peak around 0.8 ns. The mean lifetime, and particularly its second component, can be useful to distinguish resilin-rich from resilin-poor parts of the cuticle. The few existing literature data suggest that chitin is unlikely responsible for the main autofluorescent component observed in the resilin-poor areas in our study and that melanin requires further scrutiny. Autofluorescence lifetime measurements can help to characterise properties of the arthropod cuticle, especially when coupled with multiphoton excitation to allow for deeper tissue penetration.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.009
       
  • Autofluorescence lifetime variation in the cuticle of the bedbug Cimex
           lectularius
    • Authors: Klaus Reinhardt; Hans Georg Breunig; Karsten König
      Abstract: Publication date: Available online 22 December 2016
      Source:Arthropod Structure & Development
      Author(s): Klaus Reinhardt, Hans Georg Breunig, Karsten König
      The decay time of the fluorescence of excited molecules, called fluorescence lifetime, can provide information about the cuticle composition additionally to widely used spectral characteristics. We compared autofluorescence lifetimes of different cuticle regions in the copulatory organ of females of the bedbug, Cimex lectularius. After two-photon excitation at 720 nm, regions recently characterised as being rich in resilin showed a longer bimodal distribution of the mean autofluorescence lifetime τm (tau-m) at 0.4 ns and 1.0–1.5 ns, while resilin-poor sites exhibited a unimodal pattern with a peak around 0.8 ns. The mean lifetime, and particularly its second component, can be useful to distinguish resilin-rich from resilin-poor parts of the cuticle. The few existing literature data suggest that chitin is unlikely responsible for the main autofluorescent component observed in the resilin-poor areas in our study and that melanin requires further scrutiny. Autofluorescence lifetime measurements can help to characterise properties of the arthropod cuticle, especially when coupled with multiphoton excitation to allow for deeper tissue penetration.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.009
       
  • Autofluorescence lifetime variation in the cuticle of the bedbug Cimex
           lectularius
    • Authors: Klaus Reinhardt; Hans Georg Breunig; Karsten König
      Abstract: Publication date: Available online 22 December 2016
      Source:Arthropod Structure & Development
      Author(s): Klaus Reinhardt, Hans Georg Breunig, Karsten König
      The decay time of the fluorescence of excited molecules, called fluorescence lifetime, can provide information about the cuticle composition additionally to widely used spectral characteristics. We compared autofluorescence lifetimes of different cuticle regions in the copulatory organ of females of the bedbug, Cimex lectularius. After two-photon excitation at 720 nm, regions recently characterised as being rich in resilin showed a longer bimodal distribution of the mean autofluorescence lifetime τm (tau-m) at 0.4 ns and 1.0–1.5 ns, while resilin-poor sites exhibited a unimodal pattern with a peak around 0.8 ns. The mean lifetime, and particularly its second component, can be useful to distinguish resilin-rich from resilin-poor parts of the cuticle. The few existing literature data suggest that chitin is unlikely responsible for the main autofluorescent component observed in the resilin-poor areas in our study and that melanin requires further scrutiny. Autofluorescence lifetime measurements can help to characterise properties of the arthropod cuticle, especially when coupled with multiphoton excitation to allow for deeper tissue penetration.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.009
       
  • Delta-Notch signalling in segmentation
    • Authors: Bo-Kai Liao; Andrew Oates
      Abstract: Publication date: Available online 20 December 2016
      Source:Arthropod Structure & Development
      Author(s): Bo-Kai Liao, Andrew C. Oates
      Modular body organization is found widely across multicellular organisms, and some of them form repetitive modular structures via the process of segmentation. It's vastly interesting to understand how these regularly repeated structures are robustly generated from the underlying noise in biomolecular interactions. Recent studies from arthropods reveal similarities in segmentation mechanisms with vertebrates, and raise the possibility that the three phylogenetic clades, annelids, arthropods and chordates, might share homology in this process from a bilaterian ancestor. Here, we discuss vertebrate segmentation with particular emphasis on the role of the Notch intercellular signalling pathway. We introduce vertebrate segmentation and Notch signalling, pointing out historical milestones, then describe existing models for the Notch pathway in the synchronization of noisy neighbouring oscillators, and a new role in the modulation of gene expression wave patterns. We ask what functions Notch signalling may have in arthropod segmentation and explore the relationship between Notch-mediated lateral inhibition and synchronization. Finally, we propose open questions and technical challenges to guide future investigations into Notch signalling in segmentation.

      PubDate: 2016-12-23T05:04:11Z
       
  • Delta-Notch signalling in segmentation
    • Authors: Bo-Kai Liao; Andrew Oates
      Abstract: Publication date: Available online 20 December 2016
      Source:Arthropod Structure & Development
      Author(s): Bo-Kai Liao, Andrew C. Oates
      Modular body organization is found widely across multicellular organisms, and some of them form repetitive modular structures via the process of segmentation. It's vastly interesting to understand how these regularly repeated structures are robustly generated from the underlying noise in biomolecular interactions. Recent studies from arthropods reveal similarities in segmentation mechanisms with vertebrates, and raise the possibility that the three phylogenetic clades, annelids, arthropods and chordates, might share homology in this process from a bilaterian ancestor. Here, we discuss vertebrate segmentation with particular emphasis on the role of the Notch intercellular signalling pathway. We introduce vertebrate segmentation and Notch signalling, pointing out historical milestones, then describe existing models for the Notch pathway in the synchronization of noisy neighbouring oscillators, and a new role in the modulation of gene expression wave patterns. We ask what functions Notch signalling may have in arthropod segmentation and explore the relationship between Notch-mediated lateral inhibition and synchronization. Finally, we propose open questions and technical challenges to guide future investigations into Notch signalling in segmentation.

      PubDate: 2016-12-23T05:04:11Z
       
  • Origin and evolution of the panarthropod head – A palaeobiological and
           developmental perspective
    • Authors: Javier Ortega-Hernández; Ralf Janssen; Graham E. Budd
      Abstract: Publication date: Available online 18 December 2016
      Source:Arthropod Structure & Development
      Author(s): Javier Ortega-Hernández, Ralf Janssen, Graham E. Budd
      The panarthropod head represents a complex body region that has evolved through the integration and functional specialization of the anterior appendage-bearing segments. Advances in the developmental biology of diverse extant organisms have led to a substantial clarity regarding the relationships of segmental homology between Onychophora (velvet worms), Tardigrada (water bears), and Euarthropoda (e.g. arachnids, myriapods, crustaceans, hexapods). The improved understanding of the segmental organization in panarthropods offers a novel perspective for interpreting the ubiquitous Cambrian fossil record of these successful animals. A combined palaeobiological and developmental approach to the study of the panarthropod head through deep time leads us to propose a consensus hypothesis for the intricate evolutionary history of this important tagma. The contribution of exceptionally preserved brains in Cambrian fossils – together with the recognition of segmentally informative morphological characters – illuminate the polarity for major anatomical features. The euarthropod stem-lineage provides a detailed view of the step-wise acquisition of critical characters, including the origin of a multiappendicular head formed by the fusion of several segments, and the transformation of the ancestral protocerebral limb pair into the labrum, following the postero-ventral migration of the mouth opening. Stem-group onychophorans demonstrate an independent ventral migration of the mouth and development of a multisegmented head, as well as the differentiation of the deutocerebral limbs as expressed in extant representatives. The anterior organization of crown-group Tardigrada retains several ancestral features, such as an anterior-facing mouth and one-segmented head. The proposed model aims to clarify contentious issues on the evolution of the panarthropod head, and lays the foundation from which to further address this complex subject in the future.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.10.011
       
  • Cuticular microstructures turn specular black into matt black in a stick
           insect
    • Authors: Doris L. Maurer; Tobias Kohl; Michael J. Gebhardt
      Abstract: Publication date: Available online 18 December 2016
      Source:Arthropod Structure & Development
      Author(s): Doris L. Maurer, Tobias Kohl, Michael J. Gebhardt
      The stick insect Peruphasma schultei stands out from other insects by its deep matt black cuticle. We tested whether the appearance of P. schultei is due to microstructures of the cuticle, a phenomenon that has recently been described for the velvet black scales of the Gaboon viper. The shiny black stick insect Anisomorpha paromalus served as a control. We found that the P. schultei cuticle is characterised by two different types of microstructures, tall elevations with a maximum size of 18 μm and small structures with a height of 4 μm. Other than in the snake, P. schultei microstructures do not bear nanostructures. The microstructures scatter light independently of the viewing angle. This causes the matt appearance of the cuticle, whereas pigments are responsible for the black colouration, resulting in a maximum reflectance of 2.8% percent. The microstructures also cause the hydrophobic properties of the cuticle with contact angles near 130°. Resin replicas and bleaching of the cuticle strongly support these results. Moreover, the matt black cuticle has a higher heat absorption compared to the control. We discuss the selective benefit of the matt black appearance of P. schultei in the context of behaviour, ecology and phylogeny.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.006
       
  • Cuticular microstructures turn specular black into matt black in a stick
           insect
    • Authors: Doris L. Maurer; Tobias Kohl; Michael J. Gebhardt
      Abstract: Publication date: Available online 18 December 2016
      Source:Arthropod Structure & Development
      Author(s): Doris L. Maurer, Tobias Kohl, Michael J. Gebhardt
      The stick insect Peruphasma schultei stands out from other insects by its deep matt black cuticle. We tested whether the appearance of P. schultei is due to microstructures of the cuticle, a phenomenon that has recently been described for the velvet black scales of the Gaboon viper. The shiny black stick insect Anisomorpha paromalus served as a control. We found that the P. schultei cuticle is characterised by two different types of microstructures, tall elevations with a maximum size of 18 μm and small structures with a height of 4 μm. Other than in the snake, P. schultei microstructures do not bear nanostructures. The microstructures scatter light independently of the viewing angle. This causes the matt appearance of the cuticle, whereas pigments are responsible for the black colouration, resulting in a maximum reflectance of 2.8% percent. The microstructures also cause the hydrophobic properties of the cuticle with contact angles near 130°. Resin replicas and bleaching of the cuticle strongly support these results. Moreover, the matt black cuticle has a higher heat absorption compared to the control. We discuss the selective benefit of the matt black appearance of P. schultei in the context of behaviour, ecology and phylogeny.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.006
       
  • The synganglion of the jumping spider Marpissa muscosa (Arachnida:
           Salticidae): Insights from histology, immunohistochemistry and microCT
           analysis
    • Authors: Philip O.M. Steinhoff; Andy Sombke; Jannis Liedtke; Jutta M. Schneider; Steffen Harzsch; Gabriele Uhl
      Abstract: Publication date: Available online 18 December 2016
      Source:Arthropod Structure & Development
      Author(s): Philip O.M. Steinhoff, Andy Sombke, Jannis Liedtke, Jutta M. Schneider, Steffen Harzsch, Gabriele Uhl
      Jumping spiders are known for their extraordinary cognitive abilities. The underlying nervous system structures, however, are largely unknown. Here, we explore and describe the anatomy of the brain in the jumping spider Marpissa muscosa (Clerck, 1757) by means of paraffin histology, X-ray microCT analysis and immunohistochemistry as well as three-dimensional reconstruction. In the prosoma, the CNS is a clearly demarcated mass that surrounds the esophagus. The anteriormost neuromere, the protocerebrum, comprises nine bilaterally paired neuropils, including the mushroom bodies and one unpaired midline neuropil, the arcuate body. Further ventrally, the synganglion comprises the cheliceral (deutocerebrum) and pedipalpal neuropils (tritocerebrum). Synapsin-immunoreactivity in all neuropils is generally strong, while allatostatin-immunoreactivity is mostly present in association with the arcuate body and the stomodeal bridge. The most prominent neuropils in the spider brain, the mushroom bodies and the arcuate body, were suggested to be higher integrating centers of the arthropod brain. The mushroom body in M. muscosa is connected to first and second order visual neuropils of the lateral eyes, and the arcuate body to the second order neuropils of the anterior median eyes (primary eyes) through a visual tract. The connection of both, visual neuropils and eyes and arcuate body, as well as their large size corroborates the hypothesis that these neuropils play an important role in cognition and locomotion control of jumping spiders. In addition, we show that the architecture of the brain of M. muscosa and some previously investigated salticids differs significantly from that of the wandering spider Cupiennius salei, especially with regard to structure and arrangement of visual neuropils and mushroom body. Thus, we need to explore the anatomical conformities and specificities of the brains of different spider taxa in order to understand evolutionary transformations of the arthropod brain.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.003
       
  • The synganglion of the jumping spider Marpissa muscosa (Arachnida:
           Salticidae): Insights from histology, immunohistochemistry and microCT
           analysis
    • Authors: Philip O.M. Steinhoff; Andy Sombke; Jannis Liedtke; Jutta M. Schneider; Steffen Harzsch; Gabriele Uhl
      Abstract: Publication date: Available online 18 December 2016
      Source:Arthropod Structure & Development
      Author(s): Philip O.M. Steinhoff, Andy Sombke, Jannis Liedtke, Jutta M. Schneider, Steffen Harzsch, Gabriele Uhl
      Jumping spiders are known for their extraordinary cognitive abilities. The underlying nervous system structures, however, are largely unknown. Here, we explore and describe the anatomy of the brain in the jumping spider Marpissa muscosa (Clerck, 1757) by means of paraffin histology, X-ray microCT analysis and immunohistochemistry as well as three-dimensional reconstruction. In the prosoma, the CNS is a clearly demarcated mass that surrounds the esophagus. The anteriormost neuromere, the protocerebrum, comprises nine bilaterally paired neuropils, including the mushroom bodies and one unpaired midline neuropil, the arcuate body. Further ventrally, the synganglion comprises the cheliceral (deutocerebrum) and pedipalpal neuropils (tritocerebrum). Synapsin-immunoreactivity in all neuropils is generally strong, while allatostatin-immunoreactivity is mostly present in association with the arcuate body and the stomodeal bridge. The most prominent neuropils in the spider brain, the mushroom bodies and the arcuate body, were suggested to be higher integrating centers of the arthropod brain. The mushroom body in M. muscosa is connected to first and second order visual neuropils of the lateral eyes, and the arcuate body to the second order neuropils of the anterior median eyes (primary eyes) through a visual tract. The connection of both, visual neuropils and eyes and arcuate body, as well as their large size corroborates the hypothesis that these neuropils play an important role in cognition and locomotion control of jumping spiders. In addition, we show that the architecture of the brain of M. muscosa and some previously investigated salticids differs significantly from that of the wandering spider Cupiennius salei, especially with regard to structure and arrangement of visual neuropils and mushroom body. Thus, we need to explore the anatomical conformities and specificities of the brains of different spider taxa in order to understand evolutionary transformations of the arthropod brain.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.003
       
  • The synganglion of the jumping spider Marpissa muscosa (Arachnida:
           Salticidae): Insights from histology, immunohistochemistry and microCT
           analysis
    • Authors: Philip O.M. Steinhoff; Andy Sombke; Jannis Liedtke; Jutta M. Schneider; Steffen Harzsch; Gabriele Uhl
      Abstract: Publication date: Available online 18 December 2016
      Source:Arthropod Structure & Development
      Author(s): Philip O.M. Steinhoff, Andy Sombke, Jannis Liedtke, Jutta M. Schneider, Steffen Harzsch, Gabriele Uhl
      Jumping spiders are known for their extraordinary cognitive abilities. The underlying nervous system structures, however, are largely unknown. Here, we explore and describe the anatomy of the brain in the jumping spider Marpissa muscosa (Clerck, 1757) by means of paraffin histology, X-ray microCT analysis and immunohistochemistry as well as three-dimensional reconstruction. In the prosoma, the CNS is a clearly demarcated mass that surrounds the esophagus. The anteriormost neuromere, the protocerebrum, comprises nine bilaterally paired neuropils, including the mushroom bodies and one unpaired midline neuropil, the arcuate body. Further ventrally, the synganglion comprises the cheliceral (deutocerebrum) and pedipalpal neuropils (tritocerebrum). Synapsin-immunoreactivity in all neuropils is generally strong, while allatostatin-immunoreactivity is mostly present in association with the arcuate body and the stomodeal bridge. The most prominent neuropils in the spider brain, the mushroom bodies and the arcuate body, were suggested to be higher integrating centers of the arthropod brain. The mushroom body in M. muscosa is connected to first and second order visual neuropils of the lateral eyes, and the arcuate body to the second order neuropils of the anterior median eyes (primary eyes) through a visual tract. The connection of both, visual neuropils and eyes and arcuate body, as well as their large size corroborates the hypothesis that these neuropils play an important role in cognition and locomotion control of jumping spiders. In addition, we show that the architecture of the brain of M. muscosa and some previously investigated salticids differs significantly from that of the wandering spider Cupiennius salei, especially with regard to structure and arrangement of visual neuropils and mushroom body. Thus, we need to explore the anatomical conformities and specificities of the brains of different spider taxa in order to understand evolutionary transformations of the arthropod brain.

      PubDate: 2016-12-23T05:04:11Z
      DOI: 10.1016/j.asd.2016.11.003
       
  • Damage, repair and regeneration in insect cuticle: The story so far, and
           possibilities for the future
    • Authors: Eoin Parle; Jan-Henning Dirks; David Taylor
      Abstract: Publication date: Available online 8 December 2016
      Source:Arthropod Structure & Development
      Author(s): Eoin Parle, Jan-Henning Dirks, David Taylor
      The exoskeleton of an insect can contain countless specializations across an individual, across developmental stages, and across the class Insecta. Hence, the exoskeleton's building material cuticle must perform a vast variety of functions. Cuticle displays a wide range of material properties which are determined by several known factors: the amount and orientation of the chitin fibres, the constituents and degree of cross-linking and hydration of the protein matrix, the relative amounts of exo- and endocuticle, and the shape of the structures themselves. In comparison to other natural materials such as wood and mammal bone, relatively few investigations into the mechanical properties of insect cuticle have been carried out. Of these, very few have focussed on the need for repair and its effectiveness at restoring mechanical stability to the cuticle. Insect body parts are often subject to prolonged repeated cyclic loads when running and flying, as well as more extreme “emergency” behaviours necessary for survival such as jumping, wedging (squeezing through small holes) and righting (when overturned). What effects have these actions on the cuticle itself? How close to the limits of failure does an insect push its body parts? Can an insect recover from minor or major damage to its exoskeleton “bones”? No current research has answered these questions conclusively.

      PubDate: 2016-12-14T03:18:11Z
      DOI: 10.1016/j.asd.2016.11.008
       
  • Cuticle morphogenesis in crustacean embryonic and postembryonic stages
    • Authors: Polona Mrak; Urban Bogataj; Jasna Štrus; Nada Žnidaršič
      Abstract: Publication date: Available online 3 December 2016
      Source:Arthropod Structure & Development
      Author(s): Polona Mrak, Urban Bogataj, Jasna Štrus, Nada Žnidaršič
      The crustacean cuticle is a chitin-based extracellular matrix, produced in general by epidermal cells and ectodermally derived epithelial cells of the digestive tract. Cuticle morphogenesis is an integrative part of embryonic and postembryonic development and it was studied in several groups of crustaceans, but mainly with a focus on one selected aspect of morphogenesis. Early studies were focused mainly on in vivo or histological observations of embryonic or larval molt cycles and more recently, some ultrastructural studies of the cuticle differentiation during development were performed. The aim of this paper is to review data on exoskeletal and gut cuticle formation during embryonic and postembryonic development in crustaceans, obtained in different developmental stages of different species and to bring together and discuss different aspects of cuticle morphogenesis, namely data on the morphology, ultrastructure, composition, connections to muscles and molt cycles in relation to cuticle differentiation. Based on the comparative evaluation of microscopic analyses of cuticle in crustacean embryonic and postembryonic stages, common principles of cuticle morphogenesis during development are discussed. Additional studies are suggested to further clarify this topic and to connect the new knowledge to related fields.

      PubDate: 2016-12-08T02:09:27Z
      DOI: 10.1016/j.asd.2016.11.001
       
  • Drosophila Chitinase 2 is expressed in chitin producing organs for cuticle
           formation
    • Authors: Yanina-Yasmin Pesch; Dietmar Riedel; Matthias Behr
      Abstract: Publication date: Available online 19 November 2016
      Source:Arthropod Structure & Development
      Author(s): Yanina-Yasmin Pesch, Dietmar Riedel, Matthias Behr
      The architecture of the outer body wall cuticle is fundamental to protect arthropods against invading pathogens and numerous other harmful stresses. Such robust cuticles are formed by parallel running chitin microfibrils. Molting and also local wounding leads to dynamic assembly and disassembly of the chitin-matrix throughout development. However, the underlying molecular mechanisms that organize proper chitin-matrix formation are poorly known. Recently we identified a key region for cuticle thickening at the apical cell surface, the cuticle assembly zone, where Obstructor-A (Obst-A) coordinates the formation of the chitin-matrix. Obst-A binds chitin and the deacetylase Serpentine (Serp) in a core complex, which is required for chitin-matrix maturation and preservation. Here we present evidence that Chitinase 2 (Cht2) could be essential for this molecular machinery. We show that Cht2 is expressed in the chitin-matrix of epidermis, trachea, and the digestive system. There, Cht2 is enriched at the apical cell surface and the dense chitin-matrix. We further show that in Cht2 knockdown larvae the assembly zone is rudimentary, preventing normal cuticle formation and pore canal organization. As sequence similarities of Cht2 and the core complex proteins indicate evolutionarily conserved molecular mechanisms, our findings suggest that Cht2 is involved in chitin formation also in other insects.
      Graphical abstract image

      PubDate: 2016-11-23T18:59:45Z
      DOI: 10.1016/j.asd.2016.11.002
       
  • The water-repellent cerotegument of whip-spiders (Arachnida: Amblypygi)
    • Authors: Jonas O. Wolff; Michael Seiter; Stanislav N. Gorb
      Abstract: Publication date: Available online 10 November 2016
      Source:Arthropod Structure & Development
      Author(s): Jonas O. Wolff, Michael Seiter, Stanislav N. Gorb
      The cuticle of arthropods is usually composed of layers of a chitin-protein-microcomposite, a proteinaceous epicuticle and a thin lipid coating. However, in some instances a thick cement layer (cerotegument) covers the cuticle and may produce elaborate microstructures. This has previously been described for millipedes and mites. Here we report the previously unknown presence of a superhydrophobic cerotegument in whip-spiders (Ambypygi) and reveal its variation in ultrastructure and water-repellence between species. We discuss the relevance of found micro-morphological and physical characters for taxonomy and phylogenetics of this group, and the potential biological functions.

      PubDate: 2016-11-16T18:28:21Z
      DOI: 10.1016/j.asd.2016.10.010
       
  • Localization of RR-1 and RR-2 cuticular proteins within the cuticle of
           Anopheles gambiae
    • Authors: Laura Vannini; Judith H. Willis
      Abstract: Publication date: Available online 30 October 2016
      Source:Arthropod Structure & Development
      Author(s): Laura Vannini, Judith H. Willis
      The largest arthropod cuticular protein family, CPR, has the Rebers and Riddiford (R&R) Consensus that in an extended form confers chitin-binding properties. Two forms of the Consensus, RR-1 and RR-2, have been recognized and initial data suggested that the RR-1 and RR-2 proteins were present in different regions within the cuticle itself. Thus, RR-2 proteins would contribute to exocuticle that becomes sclerotized, while RR-1s would be found in endocuticle that remains soft. An alternative, and more common, suggestion is that RR-1 proteins are used for soft, flexible cuticles such as intersegmental membranes, while RR-2s are associated with hard cuticle such as sclerites and head capsules. We used TEM immunogold detection to localize the position of several RR-1 and RR-2 proteins in the cuticle of Anopheles gambiae. RR-1s were localized in the procuticle of the soft intersegmental membrane except for one protein found in the endocuticle of hard cuticle. RR-2s were consistently found in hard cuticle and not in flexible cuticle. All RR-2 antibodies localized to the exocuticle and four out of six were also found in the endocuticle. Hence the location of RR-1s and RR-2s depends more on properties of individual proteins than on either hypothesis.
      Graphical abstract image

      PubDate: 2016-11-02T17:04:01Z
      DOI: 10.1016/j.asd.2016.10.002
       
  • Changes in tarsal morphology and attachment ability to rough surfaces
           during ontogenesis in the beetle Gastrophysa viridula (Coleoptera,
           Chrysomelidae)
    • Authors: Daniel B. Zurek; Stanislav N. Gorb; Dagmar Voigt
      Abstract: Publication date: Available online 27 October 2016
      Source:Arthropod Structure & Development
      Author(s): Daniel B. Zurek, Stanislav N. Gorb, Dagmar Voigt
      Insects live in a three-dimensional space, and need to be able to attach to different types of surfaces in a variety of environmental and behavioral contexts. Adult leaf beetles possess great attachment ability due to their hairy attachment pads. In contrast, their larvae depend on smooth pads to attach to the same host plant. We tested friction forces generated by larvae and adults of dock leaf beetles Gastrophysa viridula on different rough surfaces, and found that adults generate much higher attachment to various substrates than larvae, but are more susceptible to completely losing attachment ability on surfaces with “critical” roughness. Furthermore, sex-specific setal morphology has the effect that attachment forces of male adults are generally higher than those of females when adjusted for body weight. The results are discussed in the context of development, ecology, and changing behavioral strategies of successive life stages.

      PubDate: 2016-11-02T17:04:01Z
      DOI: 10.1016/j.asd.2016.09.006
       
  • Spectral cathodoluminescence analysis of hymenopteran mandibles with
           different levels of zinc enrichment in their teeth
    • Authors: Alberto Jorge; Carlo Polidori; Javier Garcia-Guinea; José Luis Nieves-Aldrey
      Abstract: Publication date: Available online 14 September 2016
      Source:Arthropod Structure & Development
      Author(s): Alberto Jorge, Carlo Polidori, Javier Garcia-Guinea, José Luis Nieves-Aldrey
      The inclusion of Zn in insect mandibles affects their hardness and is functional to their use during feeding or reproducing. However, little is known on the chemical/structural base of Zn enrichment. Here, we found that cathodoluminescence (CL) technique revealed two different types of CL spectra in the mandibles of Hymenoptera, depending on the Zn enrichment level assessed by Energy Dispersive X-ray Spectroscopy (EDS). Individuals having negligible traces to low % of Zn in their mandible teeth (≤3 wt%) presented a wide band of luminescence in the visible range which resembled those observed in the CC structures of graphite. This spectrum is probably characteristic for un-enriched cuticle, since it did not differ from those obtained from the Zn-lacking inner part of mandibles. Individuals with moderate to high % of Zn in their mandible teeth (≥7 wt%), instead, presented additional CL peaks in the ultraviolet range. Comparisons with different minerals of Zn suggest that these peaks could be related with OZnO bonds, with hydroxyl groups and with zinc-chlorine links (in agreement with Cl high levels detected by the EDS). Being a non-destructive technique, CL allows large comparative studies of the chemistry of metal-enriched insect cuticle even using unique specimens, such as those deposited in Natural History Museums.
      Graphical abstract image

      PubDate: 2016-10-13T18:01:19Z
      DOI: 10.1016/j.asd.2016.07.001
       
  • Nano-channels in the spider fang for the transport of Zn ions to
           cross-link His-rich proteins pre-deposited in the cuticle matrix
    • Authors: Yael Politi; Eckhard Pippel; Ana C.J. Licuco-Massouh; Luca Bertinetti; Horst Blumtritt; Friedrich G. Barth; Peter Fratzl
      Abstract: Publication date: Available online 7 September 2016
      Source:Arthropod Structure & Development
      Author(s): Yael Politi, Eckhard Pippel, Ana C.J. Licuco-Massouh, Luca Bertinetti, Horst Blumtritt, Friedrich G. Barth, Peter Fratzl
      We identify the presence of multiple vascular channels within the spider fang. These channels seem to serve the transport of zinc to the tip of the fang to cross-link the protein matrix by binding to histidine residues. According to amino acid and elemental analysis of fangs extracted shortly after ecdysis, His-rich proteins are deposited before Zn is incorporated into the cuticle. Microscopic and spectroscopic investigations in the electron microscope and synchrotron radiation experiments suggest that Zn ions are transported through these channels in a liable (yet unidentified) form, and then form stable complexes upon His binding. The resulting cross-linking through the Zn–His complexes is conferring hardness to the fang. Our observations of nano-channels serving the Zn-transport within the His-rich protein matrix of the fibre reinforced spider fang may also support recent bio-inspired attempts to design artificial polymeric vascular materials for self-healing and in-situ curing.

      PubDate: 2016-09-10T14:48:04Z
      DOI: 10.1016/j.asd.2016.06.001
       
  • Exoskeletal cuticle of cavernicolous and epigean terrestrial isopods:
           A review and perspectives
    • Authors: Miloš Vittori; Magda Tušek-Žnidarič; Jasna Štrus
      Abstract: Publication date: Available online 1 September 2016
      Source:Arthropod Structure & Development
      Author(s): Miloš Vittori, Magda Tušek-Žnidarič, Jasna Štrus
      Comparative ultrastructural studies of the integument in terrestrial isopod crustaceans show that specific environmental adaptations of different eco-morphotypes are reflected in cuticle structure. The biphasic molting in isopods is a valuable experimental model for studies of cuticular matrix secretion and degradation in the same animal. The aim of this review is to show structural and functional adaptations of the tergal cuticle in terrestrial isopods inhabiting cave habitats. Exoskeletal cuticle thickness, the number of cuticular layers, epicuticle structure, mineralization, pigmentation and complexity of sensory structures are compared, with greater focus on the well-studied cave trichoniscid Titanethes albus. A large number of thinner cuticular layers in cave isopods compared to fewer thicker cuticular layers in related epigean species of similar body-sizes is explained as a specific adaptation to the cavernicolous life style. The epicuticle structure and composition are compared in relation to their potential waterproofing capacity in different environments. Cuticle mineralization is described from the functional point of view as well as from the aspect of different calcium storage sites and calcium dynamics during the molt cycle. We also discuss the nature and reduction of pigmentation in the cave environment and outline perspectives for future research.

      PubDate: 2016-09-05T14:29:57Z
      DOI: 10.1016/j.asd.2016.08.002
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.198.118.102
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016