JournalTOCs

Aquaculture International
Journal Prestige (SJR): 0.591

Citation Impact (citeScore): 2
Number of Followers: 25

Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1573-143X - ISSN (Online) 0967-6120
Published by Springer-Verlag

[2468 journals]

Can vannamei shrimp (Litopenaeus vannamei) revitalise Bangladesh’s
dying shrimp industry'
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Commercial cultivation of Litopenaeus vannamei, popularly known as white leg shrimp or vannamei shrimp, has significantly boosted the global shrimp industry over the last 10 years. Higher yield potential, increasing market demand, shorter cultivation cycles and less vulnerability to diseases prompted the major shrimp-producing countries to introduce Litopenaeus vannamei. However, as of today, no academic sources are available supporting the commercial farming of Litopenaeus vannamei in Bangladesh—an important actor in the global shrimp industry. In recent years, Bangladesh’s shrimp industry has already started to lose global competitiveness due to the deficient production (0.0347 tonne/ha) of traditionally cultivated black tiger shrimp (Penaeus monodon), which is highly susceptible to white sport syndrome diseases. This opinion article aims to spark a policy stimulation justifying the immediate policy measures to introduce high-yielding Litopenaeus vannamei species to revitalize the declining shrimp industry in Bangladesh.
  PubDate: 2023-06-01
Onion (Allium cepa) improves Nile tilapia (Oreochromis niloticus)
resistance to saprolegniasis (Saprolegnia parasitica) and reduces
immunosuppressive effects of cadmium
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: The present study investigated the protective effects of dietary Allium cepa against Saprolegnia parasitica infections and the amelioration of cadmium-induced immunosuppression in Oreochromis niloticus. Saprolegnia isolates were recovered during an outbreak of saprolegniasis in farmed O. niloticus raised in a poor aquatic environment. Isolates were identified phenotypically as S. parasitica. Results were confirmed further by ITS gene sequencing. Four fish groups were kept in water with cadmium (1.5 mg/L) and fed for 30 days on a diet supplemented with crude or alcoholic extracts of A. cepa using two concentrations (0.5% or 1%). Positive (with Cd) and negative (without Cd) control fish groups were given the basal diet. The 96 h LC50 value of Cd in tilapia was (15.1 mg/L Cd). Fish exposed to Cd showed poor growth performance parameters, abnormal biochemical measurements, impaired immunological responses, and high oxidative stress indicators. Feeding tilapia on A. cepa-supplemented diets enhanced their growth performance (WG, SGR) and improved the nonspecific immune responses (WBCs, total protein, globulins, lysozyme, myeloperoxidase, and antiproteases). The inclusion of A. cepa in the diets reduced the oxidative stress (GST, SOD) and significantly decreased fish mortality after the challenge with S. parasitica. Dietary supplementation with A. cepa reduced cadmium accumulation in fish organs and up-regulated IL-1β and IFNɣ levels. The most favorable benefits were obtained by the addition of 0.5% A. cepa extract. Our results highlight the immunostimulatory properties of A. cepa dietary supplementation for farmed tilapia and recommend its use prophylactically to control saprolegniasis and mitigate cadmium adverse effects.
  PubDate: 2023-06-01
Use of dietary β-mannanase supplementation to increase nutrient
digestibility and improve growth of juvenile rohu (Labeo rohita) given a
feed based on plant ingredients
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: An 8-week feeding trial was conducted to evaluate the effects of β-mannanase supplementation on the growth performance, body composition, nutrient digestibility, and digestive enzyme activities of juvenile rohu, Labeo rohita (7.36 ± 0.13 g) given plant-based feeds. Seven isonitrogenous (35% protein) and isolipidic (13%) feeds were used; F-diet (high fishmeal content), P-diet (high plant content), and five β-mannanase supplemented diets (0.02, 0.04, 0.06, 0.08, and 0.1%) based on P-diet. The fish were fed to apparent satiation twice a day at 9:00 and 16:00 for 56 days. There were 3 tanks of fish for each feed treatment, with 15 fish in each 70 L tank. Fish fed the diet supplemented with 0.06% β-mannanase had significantly higher final weight (FW 26.35 g) than those given the P-diet (FW 22.76 g) and growth was similar (p > 0.05) to the fish given the F-diet (FW 26.35 g). The best (p < 0.05) values of feed intake (FI), feed conversion ratio (FCR), and protein efficiency ratio (PER) were recorded in fish fed the diet containing 0.06% β-mannanase, which were not significantly different to the F-diet. Viscerosomatic index (VSI) and hepatosomatic index (HSI) increased linearly (p < 0.05) with increasing β-mannanase supplementation up to 0.06% (non-significant to F-diet) and decreased thereafter. The highest (p < 0.05) values for whole-body dry matter, crude protein, crude lipid, and crude ash were recorded in fish fed the diet containing 0.06% β-mannanase and F-diet. Furthermore, fish fed the diet containing 0.06% β-mannanase had significantly higher (p < 0.05) apparent digestibility coefficient (ADC) of dry matter (84.12%), crude protein (83.08%), crude lipid (82.90%), and crude ash (79.09%) when compared to the P-diet (66.46%, 72.59%, 69.32%, 62.59%, respectively). The activities of intestinal and hepatopancreatic amylase, protease and lipase showed an increasing trend (p < 0.05) with the increase in β-mannanase supplementation, peaking at 0.06% level (which was non-significant to F-diet) and decreased (p < 0.05) thereafter. Conclusively, β-mannanase supplementation up to 0.06% significantly improved the growth performance, whole-body composition, nutrient digestibility, and digestive enzyme activities of rohu fed plant-based diet. Broken-line regression analysis showed that 0.062% was the optimum β-mannanase level for the maximum growth performance of rohu.
  PubDate: 2023-06-01
Exploration of the optimal stocking density of red swamp crayfish
(Procambarus clarkii) larvae by using the biofloc technology
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: To explore the optimal stocking density of red swamp crayfish (Procambarus clarkii) larvae (0.0134 ± 0.001 g) by using biofloc technology, five stocking densities (50, 100, 200, 400, 600 larva/m2) in BFT (BFT50, BFT100, BFT200, BFT400, BFT600) were arranged. After 45 days of farming, the BFT50, BFT100, and BFT200 groups had higher final body weight, weight gain rate, specific growth rate, and lower residual limb rate. No significant difference was found in survival rate among all the experimental groups. Moreover, the activities of lipase and pepsin in the BFT50 group were significantly higher than those of the other four groups. The amylase activity in the BFT200 group was relatively high. The cellulase activity tended to increase with the increase of the stocking density. Furthermore, the total antioxidant capacity, superoxide dismutase, and catalase activities in BFT600 group were significantly lower than those of BFT50, BFT100, and BFT200 groups. The acid phosphatase activities of BFT200 and BFT400 were significantly higher than that of BFT600 group. In addition, concentrations of ammonia nitrogen and nitrite nitrogen in the BFT50, BFT100, and BFT200 groups were significantly lower than those in the BFT600 group. Considering that increasing stocking density can improve the economic benefits, but too high density may lead to the decline of growth performance, increase of residual limb rate, and decline of antioxidant capacity, it is suggested that the stocking density of crayfish larvae should be controlled about 200 larvae/m2 by biofloc technology.
  PubDate: 2023-06-01
Treatments for the control of Neoechinorhynchus buttnerae (Acanthocephala)
in tambaqui Colossoma macropomum
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Intensive fish farming with inadequate management can imbalance the fish-pathogen-environment relationship, culminating in diseases outbreaks. In the case of tambaqui Colossoma macropomum farming, it may be affected by acanthocephalosis, a parasitic infection without a specific and safe treatment yet. The objective of this study was to evaluate the effect of the active ingredients in trichlorfon, albendazole, piperazine, and ivermectin, as well as the non-traditional chemists calcium hydroxide and diatomaceous earth incorporated to the feed, to control Neoechinorhynchus buttnerae (Acanthocephala) in tambaqui. A 63-day trial was conducted in a completely randomized experimental design, with 7 treatments, 3 replicates each, and 54 fish per treatment. Fish were sampled for weight gain and parasite count on days 0, 15, 35, and 63. In general, the efficacy of anthelmintics was low in the treatment of N. buttnerae in tambaqui. Nevertheless, among the tested products, calcium hydroxide and diatomaceous earth showed promising results (48.2% and 36.4% efficacy, respectively), followed by ivermectin and piperazine (15.9% and 12.6%, respectively). Future studies are warranted to test longer drug administration periods, novel products, and diverse experimental conditions to treat N. buttnerae in tambaqui, to provide information to develop strategies for disease management.
  PubDate: 2023-06-01
Monitoring the secreted profile of PirAvp and PirBvp toxins from Vibrio
parahaemolyticus causing acute hepatopancreatic necrosis disease
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: The lethal PirAvp and PirBvp toxins from Vibrio parahaemolyticus are responsible for acute hepatopancreatic necrosis disease (VPAHPND) in shrimp. After causing infection in the stomach of shrimp, VPAHPND released PirAvp and PirBvp toxins into the culture medium and lead to massive sloughing of cells. These effects resulted in high mortality rate during the first 35 days after culture. However, there have not been many studies on the amount of these toxins in the culture process over time. Thus, in the present study, we use lateral flow immunoassay (LFIA) strip and ELISA to screen the concentration of pathogenic bacteria in cultured medium over time to detect the disease early. The results showed that ELISA was able to detect PirAvp and PirBvp levels at 0.043 and 0.020 μg/ml, respectively. After incubation, bacteria secrete both PirAvp and PirBvp toxins equally, but after 12 h, the secretion of PirBvp increased three times more than PirAvp. Verifying with LFIA strip showed that test strip was able to detect clearly PirAvp and PirBvp at 3 h and 107 CFU/ml. After each point time, the detectable LFIA signal increased by one dilution order. This result indicated that PirAvp and PirBvp toxins were secreted over time, which help to study the role of these toxins in the pathogenic process. Furthermore, LFIA strip can be used for early detection of AHPND to help reduce economic losses for shrimp farmers.
  PubDate: 2023-06-01
Assessing the effects of dietary live prey versus an artificial compound
feed on growth performance, immune response, and intestinal microflora of
largemouth bass Micropterus salmoides
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: The largemouth bass Micropterus salmoides is a carnivorous fish species that is widely farmed in China using artificial compound feeds. Alterations from its natural diet affect intestinal microbiota structure and growth performance and can reduce disease and stress resistance. In this study, we examined growth performance, immunity, intestinal microflora, and resistance to Aeromonas veronii infections-fed prey fish (PF) and artificial compound feed (ACF). Weight gains in the PF group were 27% significantly (P < 0.05) greater than the ACF group. Antioxidant enzyme activities of superoxide dismutase, catalase, and glutathione peroxidase and mRNA expression of inducible nitric oxide synthase, transforming growth factor β1, and interleukin 10 were also significantly higher than for the ACF group. In contrast, levels of malondialdehyde were lower for the PF group consistent with the antioxidant activities. These results indicated that the commercial artificial compound diet reduced the immunity and anti-stress ability of the fish. Survival in against A. versonii infection were similar although the PF fish resisted the infection to a greater extent and succumbed at a slower rate. The gut microbiomes also differed between the PF and ACF feeding groups and operational taxonomic units were 1105.75 and 971.63, respectively. The high abundance of Verrucomicrobia were associated with weight gain and enhanced immunity for the PF group and were significantly (P < 0.05) higher than that in ACF group. Bacteroidetes abundance was closely related to weight loss in the ACF group. The results of this study suggest that the changes in intestinal microflora structure caused by dietary changes in largemouth bass affected its growth performance and reduce its immune and anti-stress abilities and provide a theoretical basis for the improvement of largemouth bass compound feeds.
  PubDate: 2023-06-01
Impacts of COVID-19-induced lockdown and key reforms in the Indian
fisheries sector—a stakeholders’ perspective
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: The COVID-19 pandemic-induced lockdown has indisputably affected the aquaculture industry across the globe. India imposed a nationwide lockdown to contain the outbreak of COVID-19 that disrupted normalcy and economic activities. The fisheries sector was also highly affected. Hence, a study was conducted from July to December 2020 to understand the stakeholders’ perception of the impact of COVID-19 lockdown, wherein 517 stakeholders participated (online) in the first stage. The policy reforms suggested by the stakeholders were referred to the fisheries experts in the second stage for prioritization towards implementation. Data analysis depicted that a majority (81%) of the stakeholders were aware of COVID-19 lockdown impacts on their businesses. Due to this unprecedented lockdown, labour availability was hampered, transport facilities were fully halted and access to inputs like seed, feed, and advisory were largely affected. Importantly, all stakeholders unanimously adduced to the uncertainty over the future of the fisheries sector. Moreover, fishery experts feel that enabling policies for the promotion of awareness, appropriate training, and transparency in the implementation of schemes, credit facilities, and price regulation can have a massive positive impact. Furthermore, the study also recommends utilizing the potential of e-resources (ICTs and IoT) to digitize the business networking of fishery sector stakeholders.
  PubDate: 2023-06-01
Effect of shrimp farm effluent (SFE) on growth, survival, regeneration,
and biochemical composition in indigenous red seaweed Gracilaria corticata
var. cylindrica
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: The growth and biochemical profile of the red seaweed Gracilaria corticata var. cylindrica was evaluated after in vitro cultivation with effluent from a shrimp Litopenaeus vannamei farming pond. Seaweeds were cultivated for 21 days in sterilized seawater enriched with shrimp effluent with 5 different concentrations (0.1, 1, 10, 50, and 100 mL L−1). Fragments with 50 and 100 mL L−1 showed a higher significant growth rate of 3.53 ± 0.08% and 3.7 ± 0.55% respectively compared to sterilized seawater as control (2.5 ± 0.15%). Survival and regeneration of fragments were higher in the treatments 10, 50 and 100 mL L−1. A 100% survival was observed in 10 and 100 mL L−1, while 100-mL L−1 showed 100% regeneration in fragments. The number of branchlets developed per fragment was observed higher (2.33 ± 0.52) and (2.23 ± 0.05) in 50 and 100 mL L−1 respectively. A 50 mL L−1 showed the highest (124.45 ± 9.28 µg g−1) chlorophyll-a, and 100 mL L−1 showed the highest (54.5 ± 5.42 µg g−1) chlorophyll-b content. Agar yield (2.8 ± 0.32% FW), total sugar (72.6 ± 2.7%), and 3,6-anhydrogalactose (8.77 ± 0.63%) was observed highest in 100 mL L−1 treatment of shrimp effluent, while sulphate content (1.5 ± 0.8%) found higher in 50 mL L−1. Results showed that effluent treatments positively affected G. corticata var. cylindrica growth and biochemical composition, especially 50 and 100 mL L−1, which could be considered a good bio-stimulator for the making of the seedling. This work presents the potential use of effluents from shrimp cultivation as fertilizer, improving the growth and seedling production for sustainable cultivation of endemic red seaweed Gracilaria corticata var. cylindrica.
  PubDate: 2023-06-01
Design, fabrication, and evaluation of a low-cost portable solar dryer for
shrimp feeds
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Feed cost is the largest component in shrimp farming which accounts for more than 50% of the operational cost. The moisture content of the feed should be less than 12% to prevent spoilage and to extend the shelf life of the feed. Though there are many dryers for drying agriculture products, a low-cost indigenous design is not available for drying shrimp feeds. Hence, a portable drying unit for shrimp feed has been designed, fabricated, and evaluated for its drying efficacy for the usage of small-scale shrimp farmers. The solar dryer is based on the principle of flat plate solar collector and greenhouse effect. The dryer unit was fabricated with 3 decks of metal mesh with trays. The whole structure is enclosed in a polycarbonate housing with glass material as a thermal collector to concentrate solar energy thus combining greenhouse heating and concentrated thermal collection for drying. Evaluation trials were conducted to monitor the temperature profile, loss on drying, and moisture removal rate of the shrimp feeds as per the standard methodology. Moreover, the drying performance was evaluated by comparing it with oven and the traditional sun drying. Properties of the feeds dried with different drying methods were compared. The developed portable solar dryer was evaluated to be efficient for shrimp feed drying.
  PubDate: 2023-06-01
Phenoloxidases from black tiger shrimp (Penaeus monodon): gene expression
and activity distribution in different tissues
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: In this study, the expression of four reference genes (β-actin, EF1-α, GAPDH, and SubF0), two prophenoloxidase genes (proPO1 and proPO2), and the distribution of phenoloxidase (PO) activity in eight tissues (carapace, cuticle, hemolymph, hepatopancreas, muscle, pereiopods, pleopods, and uropods) of black tiger shrimp (Penaeus monodon) were evaluated. According to the geNorm and NormFinder algorithms, the most stable reference gene or the best combinations of reference genes for the evaluation of proPO1 and proPO2 expression are SubF0 for cuticle, muscle, and uropods, EF1-α for hemolymph and pereiopods, EF1-α + SubF0 for carapace, β-actin + SubF0 for hepatopancreas, and β-actin + GAPDH for pleopods. In the hemolymph and uropods, proPO1 expression was significantly stronger than that of proPO2 (433 and 5 times higher, respectively). However, in hepatopancreas, proPO2 expression was significantly stronger than proPO1 (36 times higher). Trypsin cleaves the proPO zymogen into active PO in most of the studied tissues, except hepatopancreas. PO activity (units/mg protein) following trypsin activation varied among the tissues in the following order: uropods > hemolymph > pleopods > pereiopods > hepatopancreas > carapace > cuticle > muscle. The results indicate that proPO1 is dominant in hemolymph, whereas proPO2 is dominant in hepatopancreas. Altogether, these results contribute to the elucidation of the phenoloxidase function in P. monodon.
  PubDate: 2023-06-01
Regulation of light quality on lipid production, biodiesel quality, and
nutritional quality of Phaeodactylum tricornutum
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Light quality is important for microalgal biomass and bio-component accumulation. In this study, 8 kinds of combined monochromatic red (R) and blue light (B) were employed to grow Phaeodactylum tricornutum using white light (W) as a control. The results indicated that P. tricornutum had the highest specific growth rate under white light, reaching 0.151 (day−1), and the highest biomass (dry weight), reaching 302.77 mg L−1. The red light and 2R5B were the best for P. tricornutum producing carotenoids and protein, respectively. Carbohydrate was not significantly affected by light quality. The lipid content and lipid production under 5R2B were the highest, reaching 27.85% (per dry weight) and 75.56 mg/L (per culture), respectively. The best production of palmitic acid (C16:0), palmitoleic acid (C16:1 (n7)), and eicosapentaenoic acid (EPA, C20:5 (n3)) was observed at 4R3B, red light, and 1R6B respectively. The highest proportions per total fatty acids of C16:0, C16:1 (n7), and EPA were determined as 26.57%, 60.59%, and 13.87%, which were 15.71%, 11.37%, and 29.49% higher than those under white light, respectively. Compared with white light, cells that were grown under blue light, red light, and 1R6B revealed the improved lipid nutrition quality, reduced AI and TI values, increased HI (h/H) values, and increased n3:n6 ratios (under 1R6B only). Combined monochromatic light (except 1R6B) produced biodiesel with higher CN values, lower DU and IV values, and higher oxidation stability, but slightly reduced fluidity at low temperatures. The manipulated spectrum or light quality is a promising strategy to regulate the product property of P. tricornutum cultures.
  PubDate: 2023-06-01
Effect of water temperature on growth, blood biochemistry, digestive,
metabolic enzymology, and antioxidant defences of Trachinotus blochii
juveniles
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: An experiment was conducted for 6 weeks to determine the effect of elevated water temperature on growth, feed utilisation, blood biochemistry, digestive and metabolic enzyme activity, and antioxidant defences of juvenile snubnose pompano, Trachinotus blochii. One hundred and eighty snubnose pompano juveniles with an average weight of 4.01 ± 0.1 g were randomly stocked in five treatments, each with triplicates in 300 L capacity tanks. Five treatments, namely T29, T30, T31, T32, and T33, were maintained with different constant water temperatures of 29, 30, 31, 32, and 33 °C, respectively. The experimental fish were fed to apparent satiation with a diet containing 40% crude protein and 6% crude lipid twice daily throughout the experimental period. Growth response in terms of body gain (BG) and body gain percentage (BG%) showed a significant difference (P < 0.05) among the treatments, and higher BG (7.35 ± 0.04 g) and BG% (183.80 ± 4.94%) were noticed in T32 group. The feed efficiency, protein efficiency ratio, and protein productive values were significantly different (P < 0.05) among the treatments. Better performance was observed in the T32 group, and a lower performance was noticed in the T33 group. The intestinal protease and lipase activities showed an increasing trend as the water temperature increased and statistically higher activities 75.95 ± 1.46 nmol of tyrosine released min−1 mg protein−1 and 2.98 ± 0.047 nmol of pNP released min−1 mg protein−1, respectively, were recorded in the T32 group and these activities were reduced at 33 °C water temperature. Superoxide dismutase and catalase activities of experimental fish liver, gill and serum samples showed an increasing trend as the water temperature was increased in the treatments. Serum triglycerides, cholesterol, total lipid, and phospholipid contents showed a decreasing trend as the water temperature rose in the treatments and higher values of 127.38 ± 2.08, 88.67 ± 1.65, 370.79 ± 4.07, and 154.73 ± 1.20 mg dL−1, respectively, were observed in T29 group. The results of this study revealed that snubnose pompano could be reared up to 32 °C without any adverse changes in growth, survival and antioxidant responses.
  PubDate: 2023-06-01
Outbreak simulation of Litopenaeus vannamei recovery rate with oral
alginate and spirulina diet supplementation against Vibrio
parahaemolyticus AHPND
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Globally , Vibrio parahaemolyticus AHPND is the major disease outbreaks in Litopenaeus vannamei shrimp ponds and has reduced shrimp production, significantly. This study aimed to simulate the outbreak of Vibrio spp. by immersion infection at 106 CFU mL−1. After 7 days of immersion, the survived L. vannamei were then orally supplemented and treated with alginate, spirulina, and alginate + spirulina for 12 days to recover the innate immune and reduce mortality. The cellular compound, namely total hemocyte count and phagocytic activity and index, and the humoral compound, namely phenol oxidase and superoxide dismutase, were determined. The q-RT PCR was applied to measure the immune-related gene expression (ProPO, LGBP, and lectin type C). Challenged by VpAHPND intra-muscularly at 109 CFU mL−1 was the administered. After challenged, all survival rate of shrimps from supplemented diet treatments were better than control (22% ± 7.78) (p < 0.05). The best shrimp survival rate was reached at Alg 3.0 mg g−1 (50% ± 2.12) treatment. THC showed that all supplemented shrimps were significantly different (p < 0.05) from control. PA and PI parameters were not significantly (p < 0.05) different from the control. SOD activity showed that the effective treatments were SWE 5.0 µg g−1 and Alg 3.0 mg g−1 + SWE 5.0 µg g−1. Before IM VpAHPND injection at 109 CFU mL−1, PO and gene expression (ProPO and LGBP (lipopolysaccharide and β-1,3-glucan binding protein)) shrimps from Alg 3.0 mg g−1 treatment reached the best results significantly (p < 0.05) over others and all treatments decreased extremely after injection. After challenge, lectin type C gene expression was upregulated (p < 0.05) in all treatments, except control. This study shows that alginate has the ability to recover the L. vannamei survival and immune system in a dose-dependent manner.
  PubDate: 2023-06-01
Influence of BFT and water exchange systems on growth, ammonia tolerance,
and water footprint in Macrobrachium rosenbergii nursery in intensive
systems
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Nursery systems could contribute to optimizing the number of grow-out cycles per year, however need controlled environmental conditions. The aim of this work was to evaluate the effect of different aquaculture systems (biofloc technology system-BFT and the water exchange system-WES), on growth performance, ammonia resistance, and water footprint in Macrobrachium rosenbergii nursery. The experimental period lasted 58 days and the prawns of 0.15 ± 0.001 g (PL30) were stored (375 PL m−3) in eight circular tanks (400 L), with four replicates. After the experimental period, a stress test was performed using five concentrations of TAN (0, 5, 10, 20, and 40 mg L−1) for each experimental system. The final weight, weight gain, specific growth ratio, and yield were improved by the BFT system (p < 0.05). Survival was greater than 65%, with no statistical difference between the treatments (p > 0.05); therefore, water footprint in the tanks with BFT was 10 times lower than in the WES. The juveniles reared in BFT submitted to TAN were more resistant when compared than in WES. The prawns resist the concentrations of 40 mg L−1 to the BFT without affecting the survival of the prawns. The findings of the present study demonstrated that BFT effectively promoted growth performance of M. rosenbergii, ammonia tolerance, and reduction on water use.
  PubDate: 2023-06-01
Liver transcriptome analysis and identification of differentially
expressed immune gene response to Aeromonas veronii infection in Channa
argus
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: The Channa argus (C. argus), an important cultured freshwater species, is widely distributed in China, which possesses the characteristic of high disease resistance. However, the information on genomic and transcriptomic studies on disease resistance of this species is not available at present. To address the shortfall and to better understand snakehead immune response to pathogen infection at molecular level, the C. argus were challenged with potent Aeromonas veronii (A. veronii) for 24 h and the high-throughput RNA sequencing (RNA-seq) technology was employed to produce transcriptomes from the liver. Firstly, the serum parameters were significantly changed after Aeromonas veronii infection for 24 h compared with the control group. Thus, an average of 326,557,262 clean reads obtained were de novo assembled into 157,766 unigenes with most of the unigenes between 201 and 500 bp. All of unigenes were annotated to six public databases (Nr, Swiss-Prot, COG, GO, KEGG, and Pfam). A total of 21,217 differentially expressed unigenes (DEGs) were identified. The 21,217 DEGs were significantly enriched in 16 pathways related to the immune or disease. Finally, the expression levels of six selected immune-related DEGs were scrutinized. Three genes encoding TNF-α, IL-1β, and Bcl2 were significantly upregulated, whereas the gene encoding MyD88, NOD-1, and NOD-2 was significantly downregulated. In summary, this study provides valuable transcriptome resource for understanding the defense mechanisms of C. argus in resistance to pathogens from the gene expression viewpoint, which also open up the possibility to study the immune complexity and to better comprehend the interrelationships between some immune pathways in C. argus.
  PubDate: 2023-06-01
Evaluation of therapeutic potential of Streptococcus phage-1A against
Streptococcus agalactiae infection in Nile tilapia (Oreochromis niloticus)
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Streptococcus agalactiae is a highly invasive pathogen causing streptococcosis in aquaculture, globally. The potential use of lytic bacteriophage is considered as safe antimicrobials against the milieu of global antibiotic resistance in treating bacterial infections. Hence, in this study, a novel bacteriophage, Streptococcus phage-1A was isolated from infected tilapia farm against S. agalactiae. In the morphometric analysis by HR-TEM, Streptococcus phage-1A exhibited an isometric head (101.52 ± 2 nm) and short contractile tail (62.60 ± 1 nm), of the family Myoviridae. The phage has a short latent period (20 min) and high burst size of about 119 PFU/cell. PCR-based screening revealed its obligate lytic nature and could reveal the genomic diversity of the phage by RAPD. The phage was found to be stable at varying range of temperature, pH, and salinity. Protective efficiency of phage-1A was evaluated against S. agalactiae by challenge experiment in tilapia by 3 modes of application viz. IP, oral, and bath treatments. During the challenge experiment, it was found that there was a significant decrease in the count of S. agalactiae in phage treated fish organs compared to that of controls. Among the treatment trials, bath therapy was found to be more effective with 80.01% RPS comparing to IP (70.02%) and oral (50.04%) mode of administration. This is the first report on isolation, characterization, and application of bacteriophage against S. agalactiae from India and the Streptococcus phage-1A isolated in this study could demonstrate its high protective ability against streptococcal infection in tilapia.
  PubDate: 2023-06-01
Passive acoustic feeders as a tool to assess feed response and growth in
shrimp pond production
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Shrimp production has been one of the most important sectors of aquaculture for the last few decades for both its market value and consumer acceptance. The majority of shrimp feeding protocols in typical production setups rely on a combination of feed trays and predetermined feed plans which do not account for real-time consumption or feed preferences. However, for the last decade, the development of passive acoustic monitoring has allowed a much more direct measurement of shrimp feed intake by capturing and integrating clicking sounds produced by shrimp while eating. Integrating acoustic responses with automated feeding systems has allowed the development of on-demand feeding systems for shrimp. Hence, this technology is a potential tool to help understand feed preferences when the feeding protocol is based on real-time demand for feed rather than predetermined quantities. Building on previous research, the goal of this trial was to use passive feedback acoustic feeders as a tool to evaluate if shrimp prefer diets with different protein sources when given the option to eat as much as requested. A 13-week trial was conducted in 16, 0.1-ha outdoor ponds, stocked at 30 shrimp/m2 and equipped with the AQ1 acoustic feeding system. At day 45, the acoustic system was initiated, and four treatments were assigned with a 35% crude protein diet with different protein sources: all-plant, 8% poultry meal (PM), 8% fish meal (FM), and 12% FM. A second growth trial was conducted in 20, 800-L outdoor recirculating system with similar density (30 shrimp/tank), and shrimp were offered a predetermined feeding rate. We did not find statistical differences in any of the main production parameters. Results of this study indicate that shrimp did not clearly favor a particular diet. This suggests that, irrespective of ingredient matrix, a well-balanced feed will produce suitable growth even when shrimp are allowed to determine their feed intake. The use of acoustic feeders opens the door for nutrition research in which the shrimp are fed on demand.
  PubDate: 2023-06-01
An insight into the interaction between Argulus siamensis and Labeo rohita
offers future therapeutic strategy to combat argulosis
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Aquaculture and fisheries are salient flourishing sectors in the world but their sustainability is often afflicted by several pathogenic diseases. Among all the pathogenic diseases of fish, parasitic diseases are found to be a major cause of concern. Argulosis is one of the dominant parasitic problems encountered in Indian aquaculture practices. Argulus siamensis is the most prevalent argulid species harming the Indian major carp species including Labeo rohita. The major carps respond to parasitic infestation by elevating various immune relevant genes. The therapeutic chemicals, synthetic drugs and other plant extracts have made a progress in the fight against argulosis. However, there is no effective vaccine and drugs are available for this disease. Thus, designing efficient, cost-effective and eco-friendly control and treatment strategies for argulosis is presently needed. Keeping the aforementioned facts in mind, the current review elaborated the immunological interaction between A. siamensis and L. rohita, available combat tactics, highlighted the already identified vaccine candidates to design effective control measures and illustrated the use of omics technology in future to combat argulosis.
  PubDate: 2023-06-01
Partial replacement of fishmeal with Chaetomorpha algae improves feed
utilization, survival, biochemical composition, and fatty acids profile of
farmed shrimp Penaeus monodon post larvae
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Shrimp are economically important candidates for aquaculture in Tanzania; however, their farming is constrained by reliance on costly feeds, attributed to the use of fishmeal as the main ingredient. This study determined the efficacy of green algae Chaetomorpha sp. on survival, feed utilization, biochemical composition, and fatty acids profile of the cultured Penaeus monodon as a potential candidate for replacing fishmeal. Four experimental feeds, F0, F1, F2, and F3, denoting fishmeal replacement levels of 0, 10, 20, and 30%, respectively, were made. Post-larvae weighing 0.49 ± 0.06 g were stocked at 15 individuals/m3 in 2 m3 hapa nets in three replicates and reared for 45 days. The F2 treatment showed a significantly higher (p < 0.05) survival rate than the other treatments. F2 and F3 improved growth significantly with F3 exhibiting the highest weight gain (8.02 ± 0.26 g) compared to the other treatments. The biochemical composition varied significantly (p<0.05) across treatment levels. The F2 treatment demonstrated the highest muscle somatic index (MSI) of 71.77 ± 2.32%. The F3 treatment exhibited significantly higher (p<0.05) crude protein (CP) than the other treatments. Crude fat (CF) in F0 and F2 treatments were significantly higher (p<0.05) than the other replacement levels. The F0 and F1 treatments exhibited higher proportions of saturated fatty acids (SFA) than the other treatments. In contrast, F2 and F3 treatments had high levels of polyunsaturated fatty acids (PUFA). The replacement of Chaetomorpha algae at 20 to 30% levels in feeds improved feed utilization, biochemical composition, and fatty acids profile of the farmed Penaeus monodon. However, the replacement of Chaetomorpha algae at 30% resulted in high saturated fatty acids but lowest survival rates. Thus, at a 20% replacement level, Chaetomorpha algae are suitable for partial replacement of fishmeal in P. monodon feeds.
  PubDate: 2023-06-01