Bulletin of the Southern California Academy of Sciences
Open Access journal
ISSN (Print) 0038-3872
Published by Southern California Academy of Sciences [1 journal]
Open Access journal
ISSN (Print) 0038-3872
Published by Southern California Academy of Sciences [1 journal]
PubDate: Mon, 15 Sep 2014 14:27:54 PDT
- 2014 Annual Meeting Abstracts
PubDate: Mon, 15 Sep 2014 14:27:53 PDT
- Natural egg sac clutch size of the brown widow spider, Latrodectus
geometricus (Araneae: Theridiidae) in southern California
Authors: Douglas W. R. Danielsen et al.
Abstract: Abstract. We investigated egg sac clutch size of the brown widow spider, Latrodectus geometricus C. L. Koch, in southern California from June through October 2012 by counting eggs from 214 field collected egg sacs. Clutch size was fairly constant over this five-month period averaging 129.0 ± 51.0 eggs per sac with the only significant monthly difference being more eggs in September than June. Determining the relatively constant egg production for this period contributed knowledge to another project involving application of pesticide to brown widow egg sacs in attempted control of this newly established invasive pest species.
PubDate: Mon, 15 Sep 2014 14:27:50 PDT
- Psoroptes Mites and Mule Deer (Odocoileus hemionus): Additional Notes from
the San Bernardino Mountains, California
Authors: Vernon C. Bleich
Abstract: Mites of the genus Psoroptes frequently infest bighorn sheep (Ovis canadensis) in southwestern North America. Although based on a small sample (n = 15), evidence from the San Bernardino Mountains, California, previously suggested that mule deer (Odocoileus hemionus) sympatric with bighorn sheep were not infested with Psoroptes mites and, thus, were not a likely source of mites occurring on bighorn sheep. We examined 34 additional mule deer that were sympatric with bighorn sheep and detected no clinical evidence of Psoroptes infestation, providing additional support for the conclusion of Singer et al. (1997) that mule deer are unlikely sources of mites infesting bighorn sheep in the San Bernardino Mountains.
PubDate: Mon, 15 Sep 2014 14:27:49 PDT
- Responses of Small Mammals to Wildfire in a Mixed Conifer Forest in the
San Bernardino Mountains, California
Authors: Mark I. Borchert
Abstract: Abstract.—Wildfires are becoming more prevalent in montane conifer forests of the San Bernardino Mountains of southern California. The effects of fire on stand structure and composition of these forests has been extensively studied but there are far fewer studies on how wildfires affect the fauna. For five years after a wildfire in 2007, we live-trapped small mammals in three burn types: unburned, moderate-severity and high-severity. A primary objective of this study was to document the response of the small mammal community to high-severity fire. Pinyon mice were consistently more abundant in unburned forests and declined by 69-76% between unburned forests and moderate-severity and high-severity burns. In contrast, deer mice responded positively to fire. Their numbers increased by 72%-87% between unburned forests and moderate-severity and high-severity burns. Compared to unburned forests, chipmunk numbers were 43%-64% lower in moderate and high-severity burns. California ground squirrels were unaffected by either severity. Using ordination analysis, we examined the distributions of the four small mammal species in relationship to stand structure and microhabitat variables that changed after fire. When the three burn types were analyzed together, small mammal composition was significantly related to burn type (unburned vs. high-severity), years-after-fire, litter cover and cover of bare ground. When the moderate and high-severity burn types were analyzed without unburned grids, four variables were significant: years-after-fire, rock outcrop cover, bare ground cover, and the combined covers of oak resprouts and shrubs.
PubDate: Mon, 15 Sep 2014 14:27:47 PDT
- From progesterone in biopsies to estimates of pregnancy rates: Large scale
reproductive patterns of two sympatric species of common dolphin,
Delphinus spp. off California, USA and Baja, Mexico
Authors: Nicholas Marc Kellar et al.
Abstract: Blubber progesterone levels were measured in biopsy samples and used to predict the pregnancy status of 507 female common dolphins (204 long-beaked common dolphins, Delphinus capensis, and 303 short-beaked common dolphins, D. delphis). Samples were collected in the coastal waters of the eastern North Pacific between central California, USA and the southern end of Baja California, Mexico. The percentage of females pregnant was similar between the two species: 22.1% (n = 45) of D. capensis and 28.1% (n = 85) of D. delphis. For both species we found strong geographic patterns in pregnancy, suggesting that some areas were more conducive for pregnant females. A sizable drop in percent pregnant from early (38.8%, n = 133) to late (25.3%, n = 91) autumn was found in D. delphis but not in D. capensis. The potential for sample selectivity was examined via biopsies collected either from a large research ship or from a small, rigid-hull inflatable boat (RHIB) launched from the larger ship. An analysis of “Tandem Biopsy Sampling”, replicate biopsy effort on the same schools from each vessel/platform, yielded little evidence that disproportionately more pregnant female common dolphins were biopsied from one platform versus the other. This result plus an analysis of pregnancy status relative to the duration of biopsy operations failed to uncover strong evidence of unaccounted sampling bias with respect to pregnancy state. In total, these results demonstrate the utility of blubber progesterone concentrations to assess pregnancy status in free-ranging cetaceans and they highlight potential factors associated with population-level variation in dolphin pregnancy rates.
PubDate: Mon, 15 Sep 2014 14:27:44 PDT
- Status of the Endangered Scotts Valley Spineflower (Polygonaceae) in
Coastal Central California
Authors: Christopher P. Kofron et al.
Abstract: Chorizanthe robusta var. hartwegii (Scotts Valley spineflower, Polygonaceae) is a narrow endemic plant restricted to a specialized microhabitat (exposed bedrock in California prairie) in Santa Cruz County, California. This taxon and the nominate variety were listed as endangered under the U.S. Endangered Species Act in 1994. Three occurrences of C. robusta hartwegii exist on four properties in a recently urbanized area at the northern edge of the city of Scotts Valley. Ten of 80 known colonies are now likely extirpated. In 2014 the primary threats are habitat alteration due to adjacent land uses and developments, and invasive plant species (non-natives) and accumulation of thatch. Using international standards, C. robusta hartwegii is critically endangered: area of occupancy, 0.39 ha; extent of occurrence, 1.3 km2; landscape, severely fragmented; and quality of the habitat, continuing to decline. With these attributes, C. robusta hartwegii faces an extremely high risk of extinction. As a matter of urgency, we recommend reducing and controlling invasive plant species and thatch using a combination of methods: mowing with biomass removal, cutting by hand tools with biomass removal, pulling by hand with biomass removal, controlled grazing, prescribed mini-burns (testing 1 m2), and spot-treating invasive grasses with a grass-specific herbicide.
PubDate: Mon, 15 Sep 2014 14:27:42 PDT
- Population Dynamics of the Kit Fox in Western Utah
Authors: Harold J. Egoscue
Abstract: The dynamics of a kit fox, Vulpes macrotis nevadensis, population in western Utah was studied for four years coincidental with a population decline and initial recovery stages of the black-tailed jackrabbit, Lepus callfornicus desericola. The study began at least one year after the rabbits began decreasing. The presence of nonbreeding adult vixens seemingly represented the initial response of the foxes to a failing food supply. This was followed by a decline in the numbers of adults and then by smaller and fewer litters. The first sign of recovery was a return to normal sized litters. Data on natality, sex ratios, age structure, and population turnover are presented. Foxes were apparently unable to sustain themselves on available secondary prey such as kangaroo rats and appeared incapable of making adjustments in their hunting habits that enabled them to take advantage of diurnal prey.
PubDate: Mon, 15 Sep 2014 09:45:52 PDT
- The Evolution of Limb Reduction in Teiid Lizard Genus Bachia
Authors: William Presch
Abstract: The reduction pattern of limbs in the teiid lizard genus Bachia is described and discussed. The pattern which has emerged for Bachia is as follows: Reduction of the limb and girdles can be correlated with the length of the limb and the terminal structures of the appendage; the reduction is greater in the hindlimbs than the forelimbs. with the complete loss of hindlimb externally. The forelimbs are greatly reduced (down to 2-3 mm in length), but are not lost externally. Comparison of the limbs of the species of Bachia suggests that the pattern of limb formation is a result of paedomorphic development. Comparison of the limb structure with other genera of limb-reduced or limbless forms results in the construction of two possible models: 1) the loss of hindlimbs first with reduction or loss of forelimbs and 2) loss of the forelimbs with reduction, loss or modifications of the hindlimbs. The first model may represent the stages leading to the amphisbaenians, whereas, the second model probably represents the mode of limb loss in the ancestry of snakes.
PubDate: Mon, 15 Sep 2014 09:45:50 PDT
- A Study of Bryothinusa (Coleoptera: Staphylinidae), Comparing a Tabular
and a Dichotomous Key to the Species
Authors: Ian Moore
Abstract: Comparison of a tabular with a dichotomous key to the species of Bryothinusa demonstrates advantages of the former, B. rothi n. sp., Mexico and B. fluenta n. sp., Hong Kong are described.
PubDate: Mon, 15 Sep 2014 09:35:48 PDT
- Diagnosis, Systematics, and Notes on Grandidierella japonica (Amphipoda:
Gammaridea) and Its Introduction to the Pacific Coast of the United States
Authors: John W. Chapman et al.
Abstract: The introduction of Grandidierella japonica Stephensen, 1938 (Corophiidae) from Japan to Tomales Bay, Bolinas Lagoon and San Francisco Bay, California, is recorded for the first time. A diagnosis and a list of associate species are given. The possible synonymy of the genera Grandidierella and Neomicrodeutopus is indicated. This species probably arrived with oyster spat transplants from Japan.
PubDate: Mon, 15 Sep 2014 09:30:46 PDT
- First Records and Range Extensions of Crabs in California Waters
Authors: Janet Haig et al.
Abstract: Range extensions are reported for 14 species of anomuran and brachyuran crabs (Crustacea: Decapoda), six of them new to California waters. Three cold-temperate species not previously known south of the Monterey Bay area were found to occur south of Point Conception at San Miguel and Santa Rosa Islands, where a strong northern element is present in the fauna. Two species with their known northern limit of range near San Francisco Bay. and one species known only as far south as Oregon, were collected in the area of unusually cold water around Cape Mendocino.
PubDate: Mon, 15 Sep 2014 09:30:44 PDT
- Development of the Whipscorpion Schizomus floridanus, with Notes on
Behavior and Laboratory Culture
Authors: Vincent Brach
Abstract: The embryonic and larval stages of Schizomus floridanus are described, with special emphasis on the morphology of the larval tarsi. Schizomus floridainus is facultatively if not completely parthenogenetic. Females are capable of producing young after being raised apart from males for over a year. Breeding specimens were found in south Florida in August. The lack of a nesting chamber and the small number of embryos found on the brooding females resembles the situation reported for cavernicolous members of the order. A simple method of long-term culture is described, and additional notes on ecology and behavior are given.
PubDate: Mon, 15 Sep 2014 09:30:43 PDT
PubDate: Mon, 15 Sep 2014 09:25:53 PDT
- On the Affinities of Monadenia churchi Hanna and Smith (Gastropoda:
Authors: Barry Roth
PubDate: Thu, 11 Sep 2014 15:55:35 PDT
- Natural Hybridization Between Hulsea heterochroma and Hulsea vestita ssp.
Authors: Dieter H. Wilken
Abstract: Three hybridizing populations involving Hulsea heterochroma A. Gray and H. vestita Gray ssp. callicarpha (Hall) Wilken were discovered in the San Jacinto Mountains, Riverside Co, California. Population structure was investigated by means of morphological analyses, flavonoid chemistry, meiotic chromosome behavior and pollen fertility. Synthetic F1 and BC1 hybrids were employed in assessing the degree of hybridization in the three populalations. F1 hybrids were found to be heterozygous for a single reciprocal translocation and their pollen fertility was relatively high. Synthetic backcross hybrids displayed normal meiosis and high pollen fertility. On the basis of correlative studies, the hybridizing populations were found to comprise plants of both parental taxa, F1 hybrids and backcross hybrids with H. vestita ssp. callicarpha as the recurrent parent. The inability to readily distinguish most putative backcross hybrids from plants of the recurrent parent in natural populations indicates that introgression involving the two taxa should prove difficult to substantiate by traditional techniques.
PubDate: Thu, 11 Sep 2014 15:55:34 PDT
- Study on the Development of the Prior Residence Effect in Rainbow Trout
Authors: Thomas R. Payne
Abstract: Hatchery-raised rainbow trout (Salmo gairdneri, Richardson) were placed singly in small aquarium tanks for varying periods of time before the addition of a second fish. The effect of prior residence upon dominance between two fish became evident after 12 hours or more had elapsed before the addition of the second fish. The resident was more likely than the intruder to attack first, attacked in a shorter time, and had a higher potential for final dominance. The results may be applicable to the estimation of the carrying capacity of natural waterways and artificial propagation enclosures.
PubDate: Thu, 11 Sep 2014 15:50:32 PDT
- Two New Species of Errant Polychaetes From the Gulf of California, Mexico
Authors: Jerry D. Kudenov
Abstract: Two new species of errant polychaetes from the Gulf of California, Mexico, are described. A key to the species of Malmgrenia is presented.
PubDate: Thu, 11 Sep 2014 15:50:31 PDT
- Parasitism as an Indicator of Food Sources in a Cave-Adapted Salamander
Authors: William G. Dyer
Abstract: Samples of the grotto salamander, Typhlotriton spelaeus Stejneger, 1893, comprising 119 specimens, colleced in Wet Cave, Shannon Co. Missouri, were examined for gastrointestinal parasites. The parasites recovered included Haptophyra gigantea Maupas, 1879: Brachcoelium salamandrae (Froelich, 1789) Lube. 1909; Capillaria inequalis Walton,1935: C. sp.; Falcaustra catesbeianae Walton. 1929; and Oswaldocruzia sp. Comparison of parasitological findings and feeding habits revealed a definite correlation between intestinal parasitocoenosis of postmetamorphic T. spelaeus and food sources in the habitat.
PubDate: Thu, 11 Sep 2014 15:50:30 PDT
- A Study of the Morphological and Physiological Change in the
Lamellibranch, Mytilus edulis, After 6-OH-DOPA Admisistration
Authors: Anthony A. F. Paparo et al.
Abstract: Lateral ciliary activity was studied on gill preparations of the mussel Mytilus edulis. Electrical stimulation of the branchial nerve accelerated ciliary beating. The cilioexcitatory effect of electrical stimulation of the branchial nerve on the lateral ciliated cell decreased after intramuscular injection of 6-OH-DOPA. Scanning electron microscopic observations of the branchial nerve and visceral ganglion show degeneration of neuronal structures. Therefore, it appears likely that the lateral ciliated cell is dependent on the branchial nerve and visceral ganglion for its neuronal regulation.
PubDate: Thu, 11 Sep 2014 15:50:29 PDT
- Taxonomic Characters of the Genus Ochodaeus Serville with Descriptions of
Two New Species in the O. pectoralis LeConte Species Complex (Coleoptera:
Authors: David C. Carlson
Abstract: The mandibles, stridulatory peg, and male genitalia of the adults of eight species of Ochodaeus found in the United States have useful characters for the delineation of species and are described and figured. The most useful taxonomic feature of the male genitalia is the aedeagal sac. The taxonomic characters of Ochodaeus are reviewed and a key to the species of the O. pecloralis species complex is presented. The Ocliodaeus pecloralis species complex is erected to contain the nominate species O. pecloralis LeConte and two new species which are described. The other five species considered are O. biariuulus LeConte, O. inarmatus Schaeffer, O. kansanus Fall, O. praesidii Bates, and O. simplex LeConte. A lectotype is designated for O. inarmatus Schaeffer.
PubDate: Thu, 11 Sep 2014 15:50:27 PDT
PubDate: Thu, 11 Sep 2014 13:21:55 PDT