Growth, survival and fatty acids profile of Polychaete, Nereis diversicolor (Müller, 1776) cultured using waste water of great sturgeon, Huso huso (Linnaeus, 1758) at different densities in an integrated farming system

Abstract

The growth and survival of the polychaete Nereis diversicolor fed on waste water Huso huso were studied under different densities for creating the equivalence for rearing of N. diversicolor and fish stocking rate in the integrated farming system. This study was conducted to test the effect of feeding the polychaete worm Nereis diversicolor with wastewater derived different densities Huso huso. The worms with an initial mean weight of 0.05 g were fed for 55 days with wastewater of varied densities 2-3, 3-4 and 4-5 kg m-2 fish with 0.2-0.3 kg m-2 worm. Nereis fed with fish feed was as a control. The results of the present study showed that the worms were able to grow using the fish waste water. The resulting biomass and average weight of harvested worms was significantly higher in the density 3-4 kg m-2 fish treatment than in the other two treatments (p<0.05) which was lower than control. The worms from the trial NFF (Nereis fed with fish feed) showed a higher survival rate and biomass production than those from the trials in which they were fed with waste water of different densities. The findings suggest that a suspension of H. huso waste water can be used in the rearing of juvenile N. diversicolor in an integrated farming system. Certain fatty acids were abundant in worms from treatments, specifically 14:0, 16:0, C18:1n9c, 20:1, 22:1n-9, 18:3n-3, 20:2, 20:5n-3 (EPA) and 22:6n-3 (DHA), were equal between Nereis fed with waste water of different densities but significantly lower than in Nereis fed with fish feed. The results demonstrate that production of N. diversicolor using fish wastes is highly efficient. The process would consequently offer a sustainable solution to the existing problem of organic pollution. The use of worm biomass as a waste treatment method and an alternative source of FA and protein for Huso huso production systems could achieve multiple aims, including the retention of valuable lipids from the Huso huso wastes.