Bioconversion of Fish Hatchery Waste as Feed in the Production of Live Feed

Purple Non-Sulfur Bacteria (PNSB), also known as phototrophic bacteria are widely distributed in both freshwater and marine environment and capable to grow in wide range of substrates. In this study, Bacterium Rhodobacter sphaeroides strain UMS2, a freshwater isolate was used in this study in utilization of fish hatchery waste. This study was conducted to determine the nutritional values of bioprocess product that was grown in fish hatchery waste. Finally, the waste bio-converted product was used as feed supplement to monitor the growth performance of live feed Tubifex spp. Inoculum of Rhodobacter sphaeroides strain UMS2 was developed in 112 synthetic media and 48-h culture of 30% (v/v) inoculum was used in fish hatchery waste during the bioprocess. The nutritional values of bio-converted product, except total ash (%), were not significantly improved with 30% (v/v) inoculum of Rhodobacter sphaeroides, strain UMS2. Feeding trial in bloodworm (Tubifex spp.) with bioconversion product conducted for 15 days to monitor growth (w/v) of live feed. Initial growth 1.42 ± 0.001 g/L of Tubifex spp. was stocked in 15 × 75 × 15 cm plastic tray connected with recirculated system. Tubifex spp. was observed to be comparatively higher (1.55 ± 0.12 g/L) while fed in the product that contained bacterium than the growth (1.44 ± 0.15 g/L) of Tubifex spp. fed in the bioconversion product of without bacterium. The inoculums size (30%) of bacterium not enough to support the growth of Rhodobacter sphaeroides, strain UMS2 in the bioconversion process to improve the nutritional values. However, while used as feed supplement it improved the growth performance of the Tubifex spp. So, bacterium Rhodobacter sphaeroides, strain UMS2 has potentiality to be used as feed supplement in the production of live feed.

Impact of Dietary Supplementation on Bioenergetics and Reproductive Performances in Amphiprion sebae

Effects of varied types of live feeds and pelleted feeds on the bioenergetics and reproductive performances were studied under laboratory conditions.The highest feeding rate of 279.4 J/g live fish/day was observed in test fishes feed with Moina.Fish fed with pelleted feed exhibited the lowest feeding rate of 104.4 J/g live fish/day.But the absorption efficiency showed the opposite trend.The fish fed with pelleted feed showed the highest absorption efficiency 36%whereas the fish fed with Brachionus plicatilis exhibited the lowest absorption efficiency of 28%.The brood stock maintenance and larval growth were closely observed.The larvae grew like adult after 25th day of hatching.The mortality noticed during 2nd and 7th day of hatching was overcome by feeding the larvae with nutrient rich live feed.The sexually mature females and males were injected with 50μg of GnRHa(gonadotrophin releasing hormone analogue)encapsulated in a biodegradable copolymer of fatty acid dimer and sebacic acid p(FAD-SA)of a 25:75 molar ratio.After fifteen days all treated females commenced spawning.Similar treatment induced a two-fold increase in sperm volume in male.Conclusion of the present study indicated that the laboratory scale production of marine clown fish,Amphiprion sebae can be successfully carried out using live feed than the pellet feeds which express better feeding rate,spawning and development.