Substitution of water hyacinth in the diet of grey mullet Mugil cephalus (L) fry reared in the laboratory

Abstract

The effect of substituting fish feeds on the growth of Mugil cephalus fry, at various levels (20%, 30% and 40%) of dried water hyacinth, Eichhornia crassipes to reduce cost of fish production, was determined over a period of six weeks (42 days) in lagoon water condition in the laboratory. Eighty fry were used and there were four feeding regimes with a replicate for each regime, at 10 specimens per tank. The higher gain in weight of 0.39 g (125.81%) was recorded in the fry fed with 40% water hyacinth substitution diet. The higher gain in length of 1.0 cm (40.0%) was recorded in the control (100% Coppens feed). The higher condition factor was 2.59 in the 40% water hyacinth substitution diet. The better food conversion ratio, the higher food conversion efficiency and the higher specific growth rate were 2.51, 39.78% and 0.86 g/day respectively in the 40% water hyacinth diet. The economic analyses further reflected the benefit of the cost of production using 40% water hyacinth meal in M. cephalus feed for good yield and reduction in the cost of fish production.