​​Nursery Rearing of Penaeus vannamei in Biofloc Systems with Different Salinities and Organic Carbon Sources

Background: Nursery rearing of Penaeus vannamei became inevitable in the Indian shrimp farming industry, since intensification of culture practices in grow-out systems caused nitrogenous wastes accumulation, diseases, mortality and premature harvests resulted in high food conversion ratio, lower production and profits. The nursery rearing in traditional water exchange systems often getting failure because of nitrogenous waste accumulation. Hence, the present experiment was planned to rear P. vannamei in bioflocs systems (BFS) with different salinities and carbon sources. Methods: The experiment was conducted in 0.22 m3 tanks with three different salinity groups viz., 35 ppt, 20 ppt and 5 ppt and in each salinity sugar, molasses used as carbon sources to maintain an estimated C/N ratio of 15:1 and controls without carbon sources. Experimental tanks were stocked @6 post larvae/l, with pre-salinity acclimatized P.vannamei seeds having 0.0029±0.0003g size and nursed for a period of 5 weeks. Result: The nitrogenous waste accumulation was reduced significantly (p less than 0.05), also average body weight and survival rate of the seeds showed significant difference (p less than 0.001) between treatments and controls and within treatments (p less than 0.05). Salinity, carbon sources and their interaction influenced the growth characteristics significantly (p less than 0.01). The present experiment manifested promising results of bioflocs nurseries in rearing of P. vannamei seeds at different salinities.

The implementation strategy of Ecosystem Approach to Aquaculture (EAA) shrimp commodities in Pinrang District, South Sulawesi

This study aims to develop a strategy for the sustainability of shrimp aquaculture using an ecosystem approach or EAA in Pinrang Regency, South Sulawesi. A series of analyzes were carried out, namely the environmental carrying capacity analysis of aquaculture using pond environmental feasibility standards, analysis of critical factors for the sustainability of aquaculture using multidimensional scaling analysis, analysis of the sustainability status of aquaculture using pairwise comparison analysis and analysis of shrimp aquaculture management strategies based on EAA. using hierarchy process analysis. The results showed that the following strategies were needed: a) accelerating spatial planning and implementing programs in accordance with the directions for spatial use and control; b) institutional strengthening of capital cultivators in order to complement and improve facilities and infrastructure in accordance with the SOP; and c) increasing the level of education and providing a social and economic security system for members of the shrimp farming community

Adoption of Vietnamese Good Agricultural Practices (VietGAP) in Aquaculture: Evidence From Small-Scale Shrimp Farming

The increasing demand by international customers for high-quality shrimp products has led to the introduction of various certificates of traceability intended to validate quality products in Vietnam. The Vietnamese good agricultural practices (VietGAP), better known in aquaculture as the Vietnamese good aquaculture practices, has emerged as a reliable certificate for small-scale farmers and a prerequisite for international certification. This study investigates factors affecting applications for VietGAP by small-scale shrimp farmers in Vietnam. Cost-benefit analysis and binary logistic regression approaches were used to categorise shrimp farms with and without VietGAP certification. Findings indicated that while the adoption of VietGAP raised production costs by 14.5 %, it could increase net profit by up to 22 %. The increase in net profit is from increased productivity and antibiotics and chemical-free products in shrimp farming, helped fetch better prices. The results also revealed three factors that positively influenced the farmers’ decision to acquire VietGAP; education, farm size, and production system. Shrimp farmers with longer schooling years, larger farms, and those who possess cooperative/farming cluster membership are more likely to acquire VietGAP certification. The results imply that the VietGAP certification should be better promoted to cooperative production forms of farming, by strengthening the schooling year of farmers and increasing awareness of VietGAP certification to farmers who operate shrimp farms of 5,000–9,000 m2.

Identification of plant genetic resources affected by shrimp farming in the southwestern coastal region of Bangladesh

The main purpose of the study was to identify the plant genetic resources (PGRs) affected by shrimp farming and to determine their magnitude of vulnerability. Data were collected from randomly selected 100 respondents, through personal interview, using an interview schedule, at Dumuria upazila of Khulna district, during 16 November 2009 to 15 February 2010. The fruit PGRs were more affected by shrimp farming than that of timber yielding and other types of PGRs. Among the 18-fruit PGRs available, all were endangered, except indigenous velvet apple, Diospyros peregrine (Gaertn.) Gürke, which was in threatened condition. Among the fruit species, banana, Musa acuminate; guava, Psidium guajava L.; jackfruit, Artocarpus heterophyllus Lam.; sapota, Manilkara zapota L. and betel nut, Areca catechu L. were in highly endangered. Among the 17-timber yielding and other plant species, only 7-PGRs were affected by shrimp farming while majority (10-PGRs) had been available in different extents. Among the vulnerable PGRs, bamboo, Bambusa bambos (L.) Voss; flame of the forest, Delonix regia (Boj. ex Hook.) Raf.; teak, Tectona grandis L.f. and banyan, Ficus benghalensis L. were endangered, while Indian ash tree, Lannea coromandelica (Houtt.) Merr.; ipil-ipil, Leucaena leucocephala (Lam.) de Wit and cool mat, Schumannianthus dichotomus (Roxb.) Gagnep. were in threatened condition. In general, the total fruit trees decreased in numbers (-74.17%) after inception of shrimp farming. On the other hand, the total numbers of timber yielding plants increased by 15.45%. From the overall consideration (irrespective of types), the number of plant population decreased (-58.10%) after inception of shrimp farming. It means that the plant species were affected by shrimp farming and became endangered. Int. J. Agril. Res. Innov. Tech. 11(2): 18-26, Dec 2021

Dietary Probiotic Pediococcus acidilactici MA18/5M Improves the Growth, Feed Performance and Antioxidant Status of Penaeid Shrimp Litopenaeus stylirostris: A Growth-Ration-Size Approach

Probiotics are increasingly documented to confer health and performance benefits across farmed animals. The aim of this study was to assess the effect of a constant daily intake of the single-strain probiotic Pedicococcus acidilactici MA18/5M (4 × 108 CFU.day−1.kg−1 shrimp) fed over fixed, restricted ration sizes (1% to 6% biomass.day−1) on the nutritional performance and metabolism of adult penaeid shrimp Litopenaeus stylirostris (initial body-weight, BWi = 10.9 ± 1.8 g). The probiotic significantly increased the relative daily growth rate (RGR) across all ration size s tested (Mean-RGR of 0.45 ± 0.08 and 0.61 ± 0.07% BWi.day−1 for the control and probiotic groups, respectively) and decreased the maintenance ration (Rm) and the optimal ration (Ropt) by 18.6% and 11.3%, respectively. Accordingly, the probiotic group exhibited a significantly higher gross (K1) and net (K2) feed conversion efficiency with average improvement of 35% and 30%, respectively. Enhanced nutritional performances in shrimps that were fed the probiotic P. acidilactici was associated with, in particular, significantly higher α-amylase specific activity (+24.8 ± 5.5% across ration sizes) and a concentration of free-glucose and glycogen in the digestive gland at fixed ration sizes of 3% and below. This suggests that the probiotic effect might reside in a better use of dietary carbohydrates. Interestingly, P. acidilactici intake was also associated with a statistically enhanced total antioxidant status of the digestive gland and haemolymph (+24.4 ± 7.8% and +21.9 ± 8.5%, respectively; p < 0.05). As supported by knowledge in other species, enhanced carbohydrate utilization as a result of P. acidilactici intake may fuel the pentose-phosphate pathway, generating NADPH or directly enhancing OH-radicals scavenging by free glucose, in turn resulting in a decreased level of cellular oxidative stress. In conclusion, the growth-ration method documented a clear contribution of P. acidilactici MA18/5M on growth and feed efficiency of on-growing L. stylirostris that were fed fixed restricted rations under ideal laboratory conditions. The effect of the probiotic on α-amylase activity and carbohydrate metabolism and its link to the shrimp’s antioxidant status raises interesting prospects to optimize dietary formulations and helping to sustain the biological and economic efficiency of the penaeid shrimp-farming industry.

Influence of Light/Dark Cycles on Body Color, Hepatopancreas Metabolism, and Intestinal Microbiota Homeostasis in Litopenaeus vannamei

In aquatic animals, the light/dark cycle acts as an important biological factor that influences the entire life cycle. Until present, evidence regarding the regulation of physiological metabolic process under different light/dark cycles is limited in Litopenaeus vannamei. In this study, we mainly investigated the effects of different light/dark cycles (12 h light/12 h dark, 0 h light/24 h dark) on the hepatopancreas metabolism and intestinal microbiota homeostasis in L. vannamei using multiomics techniques. One interesting finding was that the body color of L. vannamei became darker after dark treatment for 8 weeks. Further hepatopancreas transcriptome analysis identified down-regulated genes involved in regulating nutrition metabolism, body-color formation, diurnal rhythm, immune function, hormone levels, and posttranslational modifications. The intestinal microbiota analysis showed that dark treatment-induced alterations in intestinal bacterial abundances in L. vannamei, such as decreased (P &lt; 0.05) relative abundance of Formosa, Demequina, Lutimonas and increased (P &lt; 0.05) relative abundance of Ruegeria, Vibrio, Actibacter, Roseovarius, Ilumatobacter, and Kriegella at the genus level. The microbiota functional analysis demonstrated that the dark treatment mainly increased susceptibility of pathogens, decreased nutrition metabolism, and influenced circadian rhythm. This study indicated for the first time that constant darkness treatment darkened the body color and altered hepatopancreas metabolism and intestinal microbiota homeostasis in L. vannamei, which might give potential clues for improving the productive capacities by changing light/dark cycles in shrimp farming.