Shrimp Culture Research Articles

Quercetin as a major component of Punica granatum L. effectively controls WSSV infection and transmission in the larval shrimp culture stage

White spot syndrome virus (WSSV) is a major pathogen in shrimp culture because of its high infectivity, fast transmission speed, and high fatality rate. White spot disease (WSD), caused by WSSV poses a substantial threat to shrimp production. Therefore, it is crucial to identify effective antiviral agents to mitigate the economic loss caused by WSD. In this study, we prepared 20 ethanol extracts of Chinese herbal medicines (CHMs) and evaluated their anti-WSSV effectiveness using Litopenaeus vannamei larvae as a model. Among the tested extracts, Punica granatum L. exhibited the highest inhibition of WSSV infection at 85%, followed by Gentiana macrophylla at 79% and Isatis tinctoria L. at 63%. Quercetin, an active ingredient found in P. granatum at a concentration of 6.3 μM, increased the survival rate of WSSV-infected larvae by 30% after 72 hpi, and significantly inhibited WSSV infection. Further data from pre-incubation assays indicated that quercetin exhibited a potentially destructive effect on WSSV virions, thereby reducing the virulence and blocking viral horizontal transmission. Moreover, the high stability of the aquacultural water facilitated the continuous exchange of quercetin treatment, which further prolonged the survival time of WSSV-infected shrimp such that the survival rate was still at 13% after 5 days. These results highlight the potential application of quercetin in eliminating WSSV during shrimp larval production.

The Effect of Different Probiotic Sources on Vannamei Shrimp (Litopenaeus vannamei) Cultivation with Biofloc System

An important component in the application of biofloc is the presence of probiotic bacteria as a floc-forming agent. This study aimed to analyze the differences in the yield of vannamei shrimp in a biofloc system using commercial probiotics and independent probiotics on a laboratory scale. The study design was a completely randomized design with 3 treatments and 4 replications, including independent probiotics (IP), commercial probiotics (CP) and control (C). PM utilized an independent formula with starter bacteria Lactobacillus casei and PK contained bacteria Bacillus sp., Pseudomonas sp., Nitrosomonas sp., Aerobacter sp., Nitrobacter sp. Probiotics were fermented 24 hours before its application to the maintenance medium. A total of 15 shrimp/aquarium measuring 3.29 ± 0.48 g were reared for 27 days after the floc was first formed. The results showed that the growth and feed conversion ratio of vannamei shrimp in the biofloc system were higher than that of the control (P<0.05). Growth and feed conversion ratio between probiotic treatments did not show significantly different results (P>0.05). Survival in treatment and control groups was not significantly different (P>0.05). The observed floc volumes which increased during the rearing of vannamei shrimp were up to 6.50-7.50 mL/L. Several types of organisms found in the flock included nematodes, phytoplankton, copepods and protozoa. The observed water quality was the same in each treatment except for higher dissolved oxygen and ammonia in the control. This study recommends the use of independent probiotics in vannamei shrimp culture based on biofloc technology.

OSCILLATION OF HYDROLOGICAL PARAMETERS IN SHRIMP PONDS WITHIN MANGROVE-DOMINATED INDIAN SUNDARBANS

The survival rate of Penaeus monodon was monitored for a decade (2010-2019) in two shrimp culture ponds at Chemaguri located at Sagar Island in the Indian Sundarbans delta complex. The two ponds exhibited significant variations in terms of the survival rate of the cultured species, which is attributed to variations in nitrate, phosphate, and dissolved oxygen. The root cause of such difference is related to variation in stocking density of the cultured species (10 PL20/m2 in pond 1 and 25 PL20/m2 in pond 2) which resulted in the generation of nutrients (except silicate) and alteration of Dissolved Oxygen (DO). Optimization of stocking density and introduction of a biotreatment pond may restore and ecologically balance the situation in the shrimp culture sector of the Sundarban region.

Comparison of Growth Performance and Biochemical Components between Low-Salinity-Tolerant Hybrid and Normal Variety of Pacific White Shrimp (Penaeus vannamei).

Penaeus vannamei, a high-yield economical shrimp, is confronting germplasm degradation in the culture environments found in China, which results in a sharp drop in production. Genetic improvement by hybridization is an effective way to solve this problem. In this study, we selected the hybrid species adapted to low-salinity culture obtained by intraspecific crossing as the experimental group. The control group consisted of normal variety from the Hainan Lutai Company. The two groups of shrimps were cultured for three months under salinities of 1 PSU, 5 PSU, and 15 PSU. Growth-performance-related indicators, biochemical composition, and molting-related gene expression were examined. The results showed that at salinities of 1 PSU and 5 PSU, the survival rate and growth performance of the low-salt breeding group were better than those of the normal variety population. The digestive enzyme activity in the low-salt breeding group was higher, which was consistent with its better growth performance, and was also associated with higher triglyceride, total cholesterol, and glycogen content. Lower levels of lactic acid indicated less anaerobic metabolism and better adaptability to the environment. The amino acid and fatty acids analysis showed that levels of essential amino acids and high unsaturated fatty acids were both higher in the low-salt breeding group than in the normal variety shrimp cultured in a low-salinity environment. The expression levels of genes associated with molting (CHS, CaMKI, RXR, EcR, HSP60, and HSP70) were also higher in the low-salt breeding group than in the control group. The results indicated that the hybrid shrimp showed better growth performance and nutritional advantages compared with the normal shrimp under salinities of 1 PSU and 5 PSU. This research provides a valuable reference for subsequent genetic breeding and shrimp culture.

Water Quality Fluctuations in Shrimp Ponds During Dry and Rainy Seasons

Abstract Season and water quality are essential indicators in the life cycle of pond ecosystems. The season is a natural factor affecting the level of water quality dynamics in shrimp cultivation in ponds. This study aims to evaluate the dynamics of differences in water quality parameters in intensive Litopenaeus vannamei ponds during dry and rainy seasons. This current study applied an ex post facto causal design based on actual field conditions. During the rainy season, water quality parameters tended to fluctuate dynamically, with the parameters of phosphate (PO4), nitrite (NO2), and total organic matter (TOM) exceeding the threshold value of water quality standards for aquaculture, with a PO4 value of 0.734 mg/L, a NO2 of 0.180 mg/L, and a TOM of 101.29 mg/L. In the dry season, water quality parameters remained stable, with only the phosphate parameter showing a value above the water quality standard threshold of 0.633 mg/L. Based on the trend of fluctuations in the two seasons, a model of equation Y = 3.979 + 0.814x was made with a significance value <α (0.05), which means that the two seasons positively correlated with the impact on fluctuations of water quality in the ponds. The results of the dynamic modelling analysis showed contradictions in water quality and nutrients during rainy and dry seasons. Water quality parameters in intensive L. vannamei cultivation during dry and rainy seasons fluctuated dynamically and differed according to the type of weather conditions and the current season.

Bacterial Diversity and Antibiotic Resistance Genes Associated with the Different Farming Systems of Black Tiger Shrimp (Penaeus monodon) in Bangladesh

Microbial community inhabiting the intestine of the shrimp (Penaeus monodon) and their surrounding environments (e.g., water and sediment) is considered as a key contributing factor for the sustainable farming of shrimp. Indiscriminate application of antibiotics in aquaculture is a growing concern due to the emergence of antibiotic resistant bacteria (ARB), more specifically the antibiotic resistance genes (ARGs). The present study investigates the microbiome composition and 19 ARGs from four different shrimp farming systems; (i) cluster, (ii) extensive, (iii) semi-intensive, and (iv) improved extensive in the southwest coastal region of Bangladesh. In doing so, the study applied advanced 16S rRNA-based metagenomic sequencing to study the bacterial composition. Moreover, gene specific polymerase chain reaction (PCR) was employed to detect the ARGs in shrimp, water, and sediments of different farming systems. In the current study, bacteria from the phylum Proteobacteria and Firmicutes were predominant among the samples (n = 12) collected from the different farming systems followed by Actinobacteria, Bacteroidetes, and Cyanobacteria. Firmicutes was the predominant phylum in the gut of shrimp cultured in the cluster (relative abundance 53.33%) and semi-intensive (relative abundance 59.2%) culture systems. Results indicated that the bacterial community structure was significantly ( p < 0.05 ) distinct among gut, sediment, and water samples as well as the farming systems. The shared operational taxonomic unit (OTU) in the sediment sample (16,495) was nearly double than the gut (7,931) and water (8,513) bacterial communities. The improved extensive farming system showed 1,289 (11.05%) shared OTUs among gut, sediment, and water followed by semi-intensive (6.87%), cluster (6.27%), and extensive (5.46%) farming system. Among the tested ARGs, sul1, cat, gyrA(C), tetA, tetC, tetX, ere(A), vanR, and dfrA1 were predominant in water and sediment samples. Semi-intensive farming system had the highest prevalence of ARGs (21.05%) while the lowest prevalence was found in extensive (5.26%) farming system. Overall, the study provides a comprehensive scenario of bacterial composition and growing emergence of ARGs in shrimp farming of Bangladesh. Therefore, the production strategy must focus on the alternatives of antibiotic for shaping the shrimp cultivation technique more sustainable.

Evaluation of Bacillus spp. as Potent Probiotics with Reduction in AHPND-Related Mortality and Facilitating Growth Performance of Pacific White Shrimp (Litopenaeus vannamei) Farms.

Acute hepatopancreatic necrosis disease (AHPND) is a serious bacterial disease affecting shrimp aquaculture worldwide. In this study, natural microbes were used in disease prevention and control. Probiotics derived from Bacillus spp. were isolated from the stomachs of AHPND-surviving Pacific white shrimp Litopenaeus vannamei (22 isolates) and mangrove forest soil near the shrimp farms (10 isolates). Bacillus spp. were genetically identified and characterized based on the availability of antimicrobial peptide (AMP)-related genes. The phenotypic characterization of all Bacillus spp. was determined based on their capability to inhibit AHPND-causing strains of Vibrio parahaemolyticus (VPAHPND). The results showed that Bacillus spp. without AMP-related genes were incapable of inhibiting VPAHPND in vitro, while other Bacillus spp. harboring at least two AMP-related genes exhibited diverse inhibition activities. Interestingly, K3 [B. subtilis (srfAA+ and bacA+)], isolated from shrimp, exerted remarkable inhibition against VPAHPND (80% survival) in Pacific white shrimp and maintained a reduction in shrimp mortality within different ranges of salinity (75-95% survival). Moreover, with different strains of VPAHPND, B. subtilis (K3) showed outstanding protection, and the survival rate of shrimp remained stable among the tested groups (80-95% survival). Thus, B. subtilis (K3) was further used to determine its efficiency in shrimp farms in different locations of Vietnam. Lower disease occurrences (2 ponds out of 30 ponds) and greater production efficiency were noticeable in the B. subtilis (K3)-treated farms. Taking the results of this study together, the heat-shock isolation and genotypic-phenotypic characterization of Bacillus spp. enable the selection of probiotics that control AHPND in Pacific white shrimp. Consequently, greater disease prevention and growth performance were affirmed to be beneficial in the use of these probiotics in shrimp cultivation, which will sustain shrimp aquaculture and be environmentally friendly.

Toxicological Impacts of TiO2 Nanoparticles on Growth, Photosynthesis Pigments, and Protein and Lipid Content of the Marine Microalga Tetraselmis Suecica.

Regarding the widespread use of titanium dioxide nanoparticles (TiO2NPs) in industry, many concerns have been raised about the risks of their potential release into aquatic ecosystems. Among the marine primary producers, Tetraselmis suecica is an ecologically important microalgae species used also as live feed in the shrimp culture industry. In the present study, the impacts of TiO2NPs on growth performance, photosynthetic pigments, lipid and protein content and its interaction with the cells of T. suecica were assessed. Based on the preliminary tests and OECD suggestion, concentrations of 5, 10, 50, 100, 200 and 400mg/L TiO2NPs were applied to algal cells for 10 days. With increasing concentration, a decrease in T. suecica cell density was observed each day. TiO2NPs induced a half-maximal inhibitory concentration (IC50) of 106.26mg/L on algal cells on the 3rd day. Chlorophyll a and b contents of the microalga decreased up to 56.08% and 52.74%, respectively following the exposure to TiO2NPs at 400mg/L. TiO2NPs also decreased the algal contents of protein and lipid up to 7.21% and 50.64%, respectively at the highest concentration. Based on FTIR, FESEM with EDS and mapping analyses, the interaction of TiO2NPs with the T. suecica cells was revealed. The stocks of T. suecica could be damaged by the toxic effects of the released TiO2NPs affecting their application as live feed in mariculture.

Mplementation of Extreme Learning Machine for Water Quality Control in Vannamei Shrimp Ponds

The application of science and technology knowledge is crucial in supporting the Indonesian Government's program to increase the production of Litopenaesus Vannamei shrimp. This research collaborates with shrimp pond farmers to develop technology that supports the cultivation of vaname shrimp. The water quality affect the harvest results, and the water parameters such as pH, dissolved oxygen (DO), alkalinity, salinity, and temperature should be monitored and adjusted if the parameters exceed the predetermined limits. We have developed an Extreme Learning Machine-based water quality management system tailored to the geographic conditions of Indonesia. This tool uses sensors to read data from the pond water, which is then processed by a microcontroller and displayed in a web-based information system. This tool helps farmers determine the water conditions and condition it accordingly. Based on experimental result error dari data training adalah 0.0001 dan error pada data testing yaitu sebesar 0.1851, it can be seen the Extreme Learning Machine has good performance for this research.

Cultured Penaeus vannamei in Korea co‐infected with white spot syndrome virus and decapod hepanhamaparvovirus

AbstractIn this study, Pacific white shrimp (Penaeus vannamei), pond water, crab, Helice tridens, and live food samples were collected from farms in three provinces of Korea to investigate the presence of white spot syndrome virus (WSSV) and decapod hepanhamaparvovirus (DHPV). By polymerase chain reaction (PCR), DHPV was detected in all shrimp samples (83 of 83); among these, 41 samples were detected with WSSV. Amplicon sequencing and phylogenetic analyses indicated that all DHPV samples were classified as a novel genotype of DHPV. Additionally, the collected squid, polychaeta, and crab were also confirmed to be detected with novel genotypes of DHPV. By WSSV quantitative PCR, the average concentrations of viruses detected in shrimp and pond water samples were 2.58 × 107 copies/μL and 1.27 × 102 copies/μL, respectively. Simultaneous detection of WSSV and DHPV was observed in shrimp, pond water, and crab samples, and co‐infection with both viruses in shrimp could be demonstrated by histopathological analysis. Viral infection can result in significant economic losses in shrimp production. Therefore, precise monitoring and management of WSSV and DHPV prevalence in pond water, live food, and habitats are essential to preventing the spread of viral diseases in the Korean shrimp culture industry.

Effects of combined rice flour and molasses use on the growth performance of Pacific white shrimp (Litopenaeus vannamei Boone, 1931) applied biofloc technology

A 63-day completely random experiment with three replications was carried out to compare the effects of five different combination ratios of rice flour (R) and molasses (M) on the growth and survival rates of Pacific white shrimp (Litopenaeus vannamei Boone, 1931) postlarvae applied biofloc technology. Five biofloc (BF) treatments, including R90-M10, R70-M30, R50-M50, R30-M70, and R10-M90, formed with the addition of different combination ratios of rice flour and molasses, i.e., 90% R+10% M, 70% R+30% M, 50% R+50% M, 30% R+70% M, and 10% R+90% M, respectively, with C/N ratios of 15:1, and a control (neither rice flour nor molasses applied) was randomly arranged into the 18 plastic tanks of 1.0 m3 volume (with 0.5 m3 of water) each tank and salinity of 15‰. The postlarvae (0.095 g) were stocked into the tanks at a 150 ind. m−3 density and fed pelleted feed (40% protein). There was an improvement in growth (FMW, WG, DWG, and SGR) for all treatments. Besides, treatments with more than or equal to 30% molasses have improved SR, FCR, and FB. Especially the highest SR (94.2%) was obtained at the R70-M30, which perhaps created the highest FB (1.435 kg m−3) in this treatment. The lowest FCR (1.28) was also observed in the R70-M30 and significantly differed from the control and other treatments. Besides, water quality parameters were within the ranges recommended for Pacific white shrimp health during the experimental period. Our findings indicated the benefits of shrimp culture using the BF system when different combined ratios of rice flour and molasses were applied, of which a ratio of 70% rice flour and 30% molasses was considered as the best.

A novel medium for long-term primary culture of hemocytes of Metapenaeus ensis

The development of a suitable shrimp cell medium is essential for achieving a long-term cell culture and finite cell line of shrimps routinely. In this study, we have successfully developed an optimal shrimp cell medium that can be used for long-term in vitro culture and continuous subculture of the hemolymph cells (or hemocytes) of greasyback shrimp Metapenaeus ensis, designated as MeH cells, by shrimp serum-based and supplements-based optimization of the basic and growth medium. In this article, we have focused on the details for the preparation of the optimal shrimp cell medium by diluting and mixing of various stock solutions as well as the methods for isolation and primary culture of MeH cells.•A novel shrimp cell growth medium is developed for long-term shrimp hemocytes culture.•The preparation method of shrimp cell growth medium is successfully established.•Obvious cell activity and proliferation potential of isolated shrimp cells can be maintained beyond 30 days.

Protective effects of indigenous lactic acid bacteria in Artemia salina challenged with Vibrio parahaemolyticus: an in vitro and in silico approach

ABSTRACT Aquaculture is one of the fastest-growing sectors of the food industry and vibriosis is a major disease affecting finfish and shellfish production capabilities. In recent years, probiotics specifically lactic acid bacteria (LAB) have proven to be an environmentally friendly alternative to antibiotics to maintain aquatic animal health. In this study, five strains of indigenous LAB isolated from traditional and non-traditional sources were evaluated for their potency in the prevention of vibriosis in brine shrimp, Artemia salina as a model organism. The LAB were well tolerated at all doses, and no negative effects on the hatching ability of brine shrimps were observed when exposed to Lactiplantibacillus plantarum KCFe63 and Limosilactobacillus fermentum NCCu21. Furthermore, all the tested LAB were able to protect the brine shrimp from the pathogen Vibrio parahaemolyticus under co-exposure and pre-exposure conditions. Molecular docking analysis revealed a high binding affinity of common probiotic metabolites lactic, butyric and propionic acids to the PirAvp and PirBvp proteins of V. parahaemolyticus which can prevent toxin formation and thereby acute hepatopancreatic necrosis disease (AHPND). Overall results suggest that two strains, L. plantarum KCFe63 and L. fermentum NCCu21, are suitable candidates to reduce the incidence of vibriosis and AHPND during brine shrimp cultivation.

Effectiveness of dietary heat-killed Bacillus subtilis harboring plasmid containing 60 copies of CpG-ODN 1668 against Vibrio harveyi in Penaeus vannamei.

The cost of the purification process hinders the extensive use of cytosine phosphate guanosine-oligodeoxynucleotides (CpG-ODNs) for shrimp culture. Therefore, this study used a shuttle vector plasmid to carry 60 copies of CpG-ODN 1668 (pAD43-25_60CpG), which can replicate in Escherichia coli and Bacillus subtilis strain RIK1285. The first experiment used a reverse gavage procedure to deliver a substance (PBS [CK], pAD43-25 [P0], and pAD43-25_60CpG [P60], respectively) directly into the anterior midgut of Penaeus vannamei and transcriptome sequence analysis with a reference genome was performed to examine the expression of well-known immune-related genes. The results showed that the expression levels of immune-related genes in P60 group were significantly increased, particularly those associated with AMPs. In addition, using RT‒qPCR, the expression levels of AMP genes (LvALF, LvPEN-2, and LvPEN-3) in the P60 group may vary depending on the tissue and time point. The second experiment used dietary supplementation with three kinds of heat-killed B. subtilis (HKBS, HKBS-P0, and HKBS-P60) in 28 days of feeding experiments. The results showed that dietary supplementation with HKBS-P60 did not significantly improve shrimp growth performance and survival. However, on days 14 and 28 of the feeding regimens, alkaline phosphatase (AKP) and acid phosphatase (ACP) activity were considerably higher than in other treatments. In addition, following infection with Vibrio harveyi, AKP and ACP activity in the HKBS-P60 group was significantly higher than in other treatments, particularly at the early stage of bacterial infection. Moreover, HKBS-P60 was found to be better protected against V. harveyi infection with lower cumulative mortality (60%) compared to HKBS (90%) and HKBS-P0 (100%) at 7 days after infection. Overall, these findings confirmed that P60 could increase immunological responses in the shrimp midgut, and HKBS-P60 could be used as an effective tool to enhance the immune response and disease resistance in shrimp.

Insight into three water additives: Revealing the protective effects on survival and stress response under cold stress for Pacific white shrimp Litopenaeus vannamei.

The reproduction, development and growth of shrimp were hindered by cold stress, and even death was caused in severe cases. Moreover, huge economic losses to the shrimp aquaculture industry were caused every year by cold currents. The purpose of this study was to investigate the potential protective effects of water additives on the cold stress resistance of Pacific white shrimp (Litopenaeus vannamei) and their ability to improve the survival and stress response of the shrimp. Three potential cold-resistant additives adenosine triphosphate (A), soybean phospholipid (SP) and Clostridium butyricum (CB) on Pacific white shrimp under cold stress were added to the water with three concentrations for each additive. The mortality, activities of antioxidation enzymes and expression of anti-stress related genes in each group under cold stress were detected. The results showed that the cumulative mortality of low concentration for adenosine triphosphate (AL) and soybean phospholipid (SPL), medium concentration for soybean phospholipid (SPM) and high concentration for Clostridium butyricum (CBH) groups were significantly lower than that of the control (C) group when temperature maintained at 13°C for 6 days. Total antioxidant capacity (T-AOC) content in shrimp plasma was significantly higher, while malondialdehyde (MDA) content was significantly lower than that in the C group. Gene expression analysis showed that 0.4mg/L of adenosine triphosphate could regulate the immune defense ability and decrease apoptosis level of Pacific white shrimp under cold stress. Soybean phospholipid (2mg/L) could enhance the immune ability of hepatopancreas, and Clostridium butyricum (10mg/L) could significantly increase the expression of stress-related genes in shrimp intestine. Overall, these findings suggested that adenosine triphosphate and soybean phospholipid have the potential to be used as cold-resistant additives in Pacific white shrimp culture. This study provided valuable insights into addressing the problem of cold stress in shrimp culture.

Metagenomic Study on the Influence of Enterocytozoon hepatopenaei (EHP) Infection on the Gut Microbiota in Penaeus vannamei

Background: Enterocytozoon hepatopenaei (EHP), infects P.vannamei and causes hepatopancreatic microsporidiasis associated with severe growth retardation in shrimp culture. The influence of EHP in the shrimp gut microbiota is poorly studied, and this would be an interesting area to investigate. In this study, metagenomic approach was followed to compare the overall species richness of the gut microbiota in healthy and EHP-infected P.vannamei. Methods: Bacterial genomic DNA from gut samples of EHP-infected and healthy shrimps were profiled for the 16S rRNA gene, targeting the V3-V4 conserved region. Operational Taxonomic Units (OTUs), were identified and clustered together with a cutoff of 97% identity using UCLUST. The OTUs were then used for the computation of alpha diversity and beta diversity for each sample. Result: Gut samples from EHP-infected shrimp showed lower bacterial abundance throughout the family, class, order, and genus levels. This research also highlights that EHP not only affects the hepatopancreas of the shrimp, but it also has the ability to affect the shrimp gut, predisposing them to other opportunistic infections.

Study of trophic interactions of green mussels (Perna viridis) as bioremediation of waste for cultivation of windu shrimp (Penaeus monodon) in Gampong Alue Naga, Banda Aceh: application of IMTA system (Integrated Multi-Trophic Aquaculture)

Residual organic matter from the cultivation of Windu Shrimp (Penaeus monodon) can cause a decrease in the quality of cultured water. This study aims to examine the trophic interactions of Windu Shrimp (Penaeus monodon) and Green mussels (Perna viridis) in a polyculture system including observing growth performance, survival rate and bioremediation level of green mussels. This research was conducted in April – September 2022 in Gampong Alue Naga, Banda Aceh. Sample biota was Windu Shrimp (Penaeus monodon) (PL20) with an average length of 1.2 cm, and green mussels (Perna viridis) obtained from nature with a shell size range of 3 cm – 5 cm. Research on species composition per container volume in a polyculture system used a completely randomized design method with 4 treatment levels and 3 replications. The treatments in this study were differences in stocking density of green mussels A (0 ind/m2), B (20 ind/m2), C (40 ind/m2), and D (60 ind/m2). In this study, the number of windu stocked was the same, namely 60 fish/container with a container size of 1x1 meter. The results showed that the difference in stocking density of green mussels had a significant effect (p<0.05) on absolute growth and survival rate of Windu shrimp but had no significant effect on absolute weight and daily growth rate of Windu shrimp (p>0.05). The average daily growth rate (SGR) ranges from 10.54% - 11.98%. The lowest survival rate value was found in treatment B, which was 26.11±10.04 and the highest survival rate value is found in treatment C of 73.33±26.6. The best treatment in this study was the stocking density of green mussels of 40 ind/m2. Green mussel filtration rate ranged from 0.6 to 1.7 L/day. Application of multispecies cultivation system (polyculture) is better than monoculture system based on growth performance and filtration rate of green mussels (Perna viridis).

Meta-Analysis: The effectiveness of artificial diets to increase on survival rate of vannamei shrimp (Litopenaeus vannamei)

The use of artificial diets for shrimp culture has been widely used at this time, but it was not yet known how large the effect of artificial diets on the survival rate of Litopenaeus vannamei. This study aims to determine the effectiveness of artificial diets on on the survival rate of Litopenaeus vannamei by meta-analysis research. The measurement results obtained z-value of 5.336 and p-value of 0.001, this p-value was smaller than the significance value of 5% (0.05). Therefore, at a significant level of 95%Cl the correlation between artificial diets and the survival rate of vannamei shrimp was significant with a minimum confidence limit of 0.192 and a maximum of 0.343. Based on Egger’s test, the z-value which was the magnitude of the regression coefficient is 1.714, while the p-value of 0.086 is greater than 0.05 which indicates that the selection of articles and the results of the study were not indicated by publication bias. In addition, the p-value > 0.05 indicates that the funnel plot was symmetrical. Therefore, the results of this study are very useful theoretically in the development of artificial diets for the survival of vannamei shrimp.

CORRELATION BETWEEN WATER QUALITY PARAMETERS AND VIBRIO SP. BACTERIA CONTENT IN TRADITIONAL VANNAMEI SHRIMP (LITHOPENAEUS VANNAMEI) CULTURE

Vannamei shrimp is a species of shrimp that is frequently cultivated using conventional methods. This is because vannamei crustaceans have favorable prospects and profits. Traditional Vannamei shrimp cultivation has great development potential, but preventing parasites and diseases that originate in the pond water when cultivating shrimp is impossible. The incidence of disease is closely correlated with parameters of water quality. Pathogenic microorganisms, specifically the Vibrio sp. bacteria, are responsible for one of the prevalent maladies affecting vannamei shrimp farms. Vibrio sp. bacteria produces vibriosis, the clinical symptoms of brownish-red gills, a crimson uropod and abdominal telson, and a sluggish swimming speed. This study aimed to determine the correlation between Vibrio sp. bacteria content and water quality parameters in conventional vannamei shrimp (Lithopenaeus vannamei) cultivation. This study employed exploratory methods and purposive sampling for its sampling. Isolation of microbes using selective media containing TCBSA. The colony abundance of Vibrio sp. bacteria was calculated using the Total Plate Count method. The results showed no significant correlation between the quality of pond water and the abundance of Vibrio sp. bacteria colonies in the traditional system of vannamei shrimp (Lithopenaeus vannamei) cultivation, with a correlation value of &gt; 0.05.

Crop diversification as a household livelihood strategy under environmental stress. Factors contributing to the adoption of crop diversification in shrimp cultivation and agricultural crop farming zones of coastal Bangladesh

Environmental stressors, potentially aggravated by climate change, pose significant challenges to households whose livelihoods rely primarily on crop production in agriculture or aquaculture, particularly in countries of the Global South. In this context, diversified farming systems, or crop diversification, have been discussed as one adaptation strategy of smallholder farming households to reduce their livelihood vulnerability and increase farm resilience. In coastal Bangladesh, livelihoods based on cultivation of shrimp, prawn, fish, paddy (rice) and other crops are likely to become more vulnerable with accelerated sea level rise, extreme flooding events, cyclone activity, river bank erosion and salinization. While crop diversification in Bangladesh is still low overall, it has been increasing. To understand the factors driving the uptake of diversified cropping in different farming production contexts and allow for policy measures addressing regionally specific needs, we explore the (relative) impact and significance of relevant factors contributing to the adoption of crop diversification practices for (i) shrimp cultivation and (ii) agricultural crop farming zones. We specifically include variables representing subjectively perceived risks to study their role in climate change adaptation. Our findings are based on a quantitative household survey (n = 1188) in nine purposefully selected unions across the Bangaleshi part of the Ganges-Brahmaputra-Meghna delta to capture the diversity of the region. Our results show that the prevalence of crop diversification measures is relatively high in the shrimp cultivation zone, but relatively low in the agricultural crop farming regions. In sum, the results show that even though direct economic factors seem to be (still) more important for diversification decisions, our study also suggests that perceived environmental threats and changes can have a favourable influence on crop diversification and should hence be included in studies investigating causes for land use changes. Yet, there are significant differences with regard to the influence of specific factors on the likelihood to diversify in the two respective zones. We conclude that greater uptakes of agriculture and aquaculture diversification could represent a promising and more sustainable approach for smallholders in coastal Bangladesh given appropriate supportive institutional conditions and measures that address specific needs of local communities. A “one-size-fits-all” approach to pushing crop diversification is unlikely to produce adequate and sustainable results.