987 resultados para Shrimp culture -- Bangladesh
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Development of continuous shrimp cell lines for effective investigation on shrimp viruses remains elusive with an arduous history of over 25 years. Despite presenting challenges to researchers in developing a cell line, the billion dollar aquaculture industry is under viral threat. Advances in molecular biology and various gene transfer technologies for immortalization of cells have resulted in the development of hundreds of cell lines from insects and mammals, but yet not a single cell line has been developed from shrimp and other marine invertebrates. Though improved growth and longevity of shrimp cells in vitro could be achieved by using modified growth media this did not make any leap to spontaneous transformation; probably due to the fact that shrimp cells inhibited neoplastic transformations. Oncogenic induction and immortalization are considered as the possible ways, and an exclusive medium for shrimp cell culture and an appropriate mode of transformation are crucial. In this review status of shrimp cell line development and its future orientation are discussed
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Lack of a valid shrimp cell line has been hampering the progress of research on shrimp viruses. One of the reasons identified was the absence of an appropriate medium which would satisfy the requirements of the cells in vitro. We report the first attempt to formulate an exclusive shrimp cell culture medium (SCCM) based on the haemolymph components of Penaeus monodon prepared in isosmotic seawater having 27 % salinity. The SCCM is composed of 22 amino acids, 4 sugars, 6 vitamins, cholesterol, FBS, phenol red, three antibiotics, potassium dihydrogen phosphate and di-sodium hydrogen phosphate at pH 6.8–7.2. Osmolality was adjusted to 720 ± 10 mOsm kg-1 and temperature of incubation was 25 8C. The most appropriate composition was finally selected based on the extent of attachment of cells and their proliferation by visual observation. Metabolic activity of cultured cells was measured by MTT assay and compared with that in L-15 (29), modified L-15 and Grace’s insect medium, and found better performance in SCCM especially for lymphoid cells with 107 % increase in activity and 85 ± 9 days of longevity. The cells from ovary and lymphoid organs were passaged twice using the newly designed shrimp cell dissociation ‘‘cocktail’’.
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Empowerment is one possible approach to increase political, social and economic participation of a target group and thus decrease food insecurity among vulnerable people. The objective of this research was to evaluate a socio-economic empowerment project implemented for 8 years in rural northern Bangladesh by using secondary data from 2000 and primary data from 2009. Three hundred women were primarily selected out of all existing and active 121 women groups formed during 8 years project implementation. Standardized interviews were conducted to collect quantitative data. In addition an overall qualitative analysis included focus group discussions, the review of project summaries and discussions with implementing staff. Data was collected on socio-economic status, rice storages and food consumption. In addition knowledge was gained on current activities of the women groups. The empowerment concept implemented in this setting was successful to increase the participants’ political, social and economic engagement and visibility. Apart from that the utilization of skills for income generation led to an improvement of the socio-economic status and food insecurity became less common. Recommendations for future projects include the increase of female members among the NGO staff as well as the further follow-up and strengthening of political acceptance and visibility of the empowered participants to sustain the outcome of the project.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Groundwater is routinely analyzed for fecal indicators but direct comparisons of fecal indicators to the presence of bacterial and viral pathogens are rare. This study was conducted in rural Bangladesh where the human population density is high, sanitation is poor, and groundwater pumped from shallow tubewells is often contaminated with fecal bacteria. Five indicator microorganisms (E. coli, total coliform, F+RNA coliphage, Bacteroides and human-associated Bacteroides (HuBacteroides)) and various environmental parameters were compared to the direct detection of waterborne pathogens by quantitative PCR in groundwater pumped from 50 tubewells. Rotavirus was detected in groundwater filtrate from the largest proportion of tubewells (40%), followed by Shigella (10%), Vibrio (10%), and pathogenic E. coli (8%). Spearman rank correlations and sensitivity-specificity calculations indicate that some, but not all, combinations of indicators and environmental parameters can predict the presence of pathogens. Culture-dependent fecal indicator bacteria measured on a single date did not predict bacterial pathogens, but annually averaged monthly measurements of culturable E. coli did improve prediction for total bacterial pathogens. F+RNA coliphage were neither correlated nor sufficiently sensitive towards rotavirus, but were predictive of bacterial pathogens. A qPCR-based E. coli assay was the best indicator for the bacterial pathogens, rotavirus and all pathogens combined. Since groundwater cannot be excluded as a significant source of diarrheal disease in Bangladesh and neighboring countries with similar characteristics, the need to develop more effective methods for screening tubewells with respect to microbial contamination is necessary.
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Nitrifying bacteria were selected from shrimp farm water and sediment (natural seed) in Thailand and from commercial seed cultures. The microbial consortia from each source giving the best ammonia removal during batch culture pre-enrichments were used as inocula for two sequencing batch reactors (SBRs). Nitrifiers were cultivated in the SBRs with 100 mg NH4-N/I and artificial wastewater containing 25 ppt salinity. The two SBRs were operated at a 7 d hydraulic retention time (HRT) for 77 d after which the HRT was reduced to 3.5 d. The amounts of ammonia removed from the influent by microorganisms sourced from the natural seed were 85% and 92% for the 7 d HIRT and the 3.5 d HRT, respectively. The ammonia removals of microbial consortia from the commercial seed were 71% and 83% for these HRTs respectively. The quantity of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) was determined in the SBRs using the most probable number (MPN) technique. Both AOB and NOB increased in number over the long-term operation of both SBRs. According to quantitative fluorescence in situ hybridisation (FISH) probing, AOB from the natural seed and commercial seed comprised 21 +/- 2% and 30 +/- 2%, respectively of all bacteria. NOB could not be detected with currently-reported FISH probes, suggesting that novel NOB were enriched from both sources. Taken collectively, the results from this study provide an indication that the nitrifiers from shrimp farm sources are more effective at ammonia removal than those from commercial seed cultures.
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Fish are an important part of Bangladeshi culture and diet. Bangladesh ranks among the top five freshwater fish producers in the world. Fish are abundant in the thousands of rivers, ponds, lakes and seasonal floodplains across the country. They are a major source of protein for people living near these water bodies. In Bangladesh, many households depend on fish farming for their livelihood. By growing fish in homestead ponds, households have a consistent supply of nutritious fish and can sell the surplus for an income. The USAID-funded Cereal Systems Initiative for South Asia in Bangladesh (CSISA-BD) aimed to increase the income of farming households through increased productivity of aquaculture systems. Key activities of the project included developing and disseminating appropriate improved agricultural technology and quality fish seeds to improve livelihoods, food security and nutrition.
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The aim of this study was to determine biofloc contributions to the antioxidant status and lipid nutrition of broodstock of Litopenaeus stylirostris in relationship with their reproductive performance and the health of larvae produced. Shrimp broodstock reared with Biofloc technology (BFT) compared to Clear water (CW) exhibited a higher health status with (i) a better final survival rate during the reproduction period (52.6% in CW against 79.8% in BFT); (ii) higher glutathione level (GSH) and total antioxidant status (TAS), reduced oxidized/reduced glutathione ratio and a higher spawning rate and frequency as well as higher gonado-somatic index and number of spawned eggs. Finally, larvae from broodstock from BFT exhibited higher survival rates at the Zoe 2 (+ 37%) and Post Larvae 1 (+ 51%) stages when compared with those from females from CW treatment. The improved reproductive performance of the broodstock and higher larvae survival rate resulting from BFT treatment may be linked to the dietary supplement obtained by the shrimp from natural productivity during BFT rearing. Indeed, our study confirms that biofloc particulates represent a potential source of dietary glutathione and a significant source of lipids, particularly essential phospholipids and n-3 highly unsaturated fatty acids (HUFA) for shrimps. Thus, broodstock from BFT treatment accumulated phospholipids, n-3 HUFA and arachidonic acid, which are necessary for vitellogenesis, embryogenesis and pre-feeding larval development. The predominant essential fatty acids, arachidonic acid (ARA), eicopentaeonic acid (EPA) and docosahexaenoic acid (DHA), had levels in the eggs that were, respectively, 2.5, 2.8 and 3 fold higher for BFT compared to the CW treatment. Statement of Relevance Today, the influence of biofloc technology on shrimp broodstock is not enough described and no information was available on the larvae quality. Moreover, two key pieces of new information emerge from the present study. Firstly, biofloc is a source of further dietary lipids that can act as energetic substrates, but also as a source of phospholipids and essential fatty acids necessary to sustain reproduction, embryonic and larval development. Second, improving the reproduction of the broodstock also leads to an improvement in the quality of the larvae. We think that our research is new and important to increase knowledge on biofloc topic. We believe the paper will contribute to the development of more efficient and therefore more sustainable systems.
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Nowadays, following was expanded shrimp breeding and culture; viral diseases have been main problem which threatened shrimp industry in the country. Therefore, shrimp samples were obtained from different stages of Litopenaeus vannmei life cycle (larval, post larval, juveniles, adults and broodstocks) based on clinical signs in the breeding center and shrimp farming from Bushehr, Khozestan and Sistan and Baluchestan provinces. Viral diseases were detected by PCR (Polymerase Chain Reaction), histopathology and transmission electron microscopy (TEM) methods. Results of the PCR were indicated present white spot virus (WSV) in juveniles, sub adults and adults shrimp with medium intensity from three provinces, but it was not showed in larval and post larval stages. Histopathological sections were indicated hypertrophy and basophilic Cowdry type A formation in nucleus cells of gill, haematopoietic, lymphoid and epithelial's cuticles and intestinal tissues which was associated with small vacuoles increased in B cells of hepatopancreas tissue of infection shrimps. Transmission electronic microscopic studies were demonstrated that the length and diameter virus was detected, respectively, 300 ± 20 nm and 75 ± 5 nm. Considerable, results of the PCR were only displayed IHHNV in juvenile, adult and broodstock shrimps from breeding and farming center of Bushehr province. The main lesion pathology was formed eosinophilic Cowdry type A in nucleus cells of gill, haematopoietic, lymphoid and epithelial's cuticles and intestinal tissues. Whereas penaeid shrimps are lack specific immune system, hence, in the present study was used of marine alga (Lurensia snideria) collected from along costal Persian Gulf of Bushehr province for viral diseases were prevented. Powder alga extract were added with a ratio of 1 % to shrimp diet. Total haemocyte count (THC) and total protein plasma (TPP) were increased after 5 days of oral administration diets. When shrimps were infected by with spot virus experimentally, THC and TPP gradually were increased in both two groups (shrimps fed with diet containing alga extract and without alga extract) after 48h. Nevertheless; THC, TPP and survival of shrimp fed with diet containing alga extract were more than shrimp control in 15 days. So, oral administration Lurensia snideria extract was capable prevention infected L. vannamei via stimulant specific immune system.
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The use of antibiotics in aquaculture has been limited. Scientifics seeking for natural substitutes to prevent of aquatic animals diseases. Considering seaweeds are rich of nutritions and bioactive compounds, the purpose of this study is: investigation the potential and use possibility of native seaweeds from Persian Gulf in shrimp aquculture industry to improve growth, survival of postlarvae and to resistance against pathogens such as vibriosis. For this propose 7 macroalgae species from Bushehr province coast, inclouding: green algae (C. iyengarii), brown algae (S. angutifolium and S. ilicifolium) and red algae (L. snyderiae, K. alvarezii and G. corticata) were collected and identified. Then seaweed extracts abtained by Water, Ethanol, Methanol and Chloroform solvents by soaking method. In vitro antibacterial activity of extracts against Gr+ bacteria (S. aureus and B. subtilis) and Gr- bacteria (V. harveyi, V. alginolyticus and E. coli) was conducted by Agar diffusion, MIC and MBC methods. Antioxidant activity also by DPPH and EC50 methods was investigated. According to results of these two tests four seaweeds species (S. angutifolium, L. snyderiae, K. alvarezii and G. corticata) were selected for use in shrimp postlarvae (PL22) diets by Bio-Encapsulation (Artemia enrichment). Before of enrichment, toxicity effect of extracts to Artemia nauplii were evaluated by determination of LC50 24 h method. From results of this section Ethanol extracts were selected to bioencapsulation. After encapsulation shrimp postlarvae divided to 12 groups in triplicate, namely: C-, C+, S (200), S (400), S (600), L(200), L(400), L(600), G(300), G(600), K(300) and K(600). During 30 days of reared period C- and C+ use of basal diet and unenriched Artemia, but the other groups use of basal diet and enriched Artemia. Except C-, the shrimps in first day of culture put in 107 cfu/ml v. harveyi suspension for 30 minutes, and after water exchange 10 ml of this dose was added to reared aquaria. After 30 days survival percentage, obtained weight and SGR% were investigated. To evaluate vibrio loading, every 10 days 5 postlarvae were sampled randomly for vibrio count. Results showed that vibrio count in C- was less than the others and in C+ was more than the others. In treatments vibrio count in L(200) was the most and L(600) was the less. Survival rate in C- was the most and after that G(600) with 79.4±6.6% and then S(300) and K(600) were 73.3±7.3% and 70.6±6.6% respectively that were significantly compare the other (P < 0.01). Also the C+ was the less with 33.3±6.6% that difference was significant (P< 0.01). In this study growth parameters of all groups that fed by enriched Artemia were better than C+ (P<0.05). After cultre period 10 shrimp of every aquarium disinfected and reared for 10 days like before treatment. After 10 days the shrimps were challenged by 3×108 cfu/ml V. harveyi and mortality was recorded for 7 days. The all of animals in C- were survive but more than 90% of C+ were dead. And survival in all of treatments were better the C+ (P<0.05). The study showed the ethanol extracts of selected seaweed from Persian Gulf is a good source for growth, Survival and disease control in shrimp larviculture.
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Background Biofloc technology (BFT), a rearing method with little or no water exchange, is gaining popularity in aquaculture. In the water column, such systems develop conglomerates of microbes, algae and protozoa, together with detritus and dead organic particles. The intensive microbial community presents in these systems can be used as a pond water quality treatment system, and the microbial protein can serve as a feed additive. The current problem with BFT is the difficulty of controlling its bacterial community composition for both optimal water quality and optimal shrimp health. The main objective of the present study was to investigate microbial diversity of samples obtained from different culture environments (Biofloc technology and clear seawater) as well as from the intestines of shrimp reared in both environments through high-throughput sequencing technology. Results Analyses of the bacterial community identified in water from BFT and “clear seawater” (CW) systems (control) containing the shrimp Litopenaeus stylirostris revealed large differences in the frequency distribution of operational taxonomic units (OTUs). Four out of the five most dominant bacterial communities were different in both culture methods. Bacteria found in great abundance in BFT have two principal characteristics: the need for an organic substrate or nitrogen sources to grow and the capacity to attach to surfaces and co-aggregate. A correlation was found between bacteria groups and physicochemical and biological parameters measured in rearing tanks. Moreover, rearing-water bacterial communities influenced the microbiota of shrimp. Indeed, the biofloc environment modified the shrimp intestine microbiota, as the low level (27 %) of similarity between intestinal bacterial communities from the two treatments. Conclusion This study provides the first information describing the complex biofloc microbial community, which can help to understand the environment-microbiota-host relationship in this rearing system.
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Seasonal pathologies reduce the profitability and sustainability of the shrimp-farming industry in New Caledonia. A study was therefore conducted to estimate the effects of polyculture of blue shrimp with goldline rabbitfish or mullet on production performance and environmental quality. The fish did not affect shrimp production, and the combined shrimp/fish yields were significantly greater than the yield from shrimp monoculture. Changes in environmental quality in all treatments were few and minor throughout the culture period.
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Vibrio pathogens are causative agents of mid-culture outbreaks, and early mortality syndrome and secondary aetiology of most dreadful viral outbreaks in shrimp aquaculture. Among the pathogenic vibrios group, Vibrio alginolyticus and V. harveyi are considered as the most significant ones in the grow-out ponds of giant black tiger shrimp Penaeus monodon in India. Use of antibiotics was banned in many countries due to the emergence of antibiotic-resistant strains and accumulation of residual antibiotics in harvested shrimp. There is an urgent need to consider the use of alternative antibiotics for the control of vibriosis in shrimp aquaculture. Biofilm formation is a pathogenic and/or establishment mechanism of Vibrio spp. This study aims to develop novel safe antibiofilm and/ or antiadhesive process using PHB to contain vibrios outbreaks in shrimp aquaculture.