Survival and growth of early life stages of leaf fish (Monocirrhus polyacanthus, Heckel 1840) cultured under different stocking densities and live food densities

摘要

The objective of this study was to evaluate the effects of different live foods, (Artemia sp. and Moina minuta), and different stocking densities on the larval rearing success of the leaf fish, Monocirrhus polyacanthus. A completely randomized factorial design (3x3; three replicates) was used. Two subsequent experiments were performed for each live food, using three food densities (100, 200 and 300 prey per larva) and three stocking densities (10, 15 and 20larvaeL(-1)). Fish were fed twice a day. Water quality parameters pH (4.08-4.02), dissolved oxygen (3.7-3.6mgL(-1)), temperature (27.9-27.8 degrees C), conductivity (147.2-127.4scm(-1)) and total ammonia (0.78-0.38gL(-1)) were determined. Weight gain, specific growth rate (SGR), body mass, relative condition factor and survival were evaluated. The water quality was influenced by the live food and stocking densities. Fish fed M.minuta showed better weight gain, specific growth ratio (SGR), biomass gain, relative condition factor and survival than in the other treatment. Artemia sp. showed no improved influence on the larvae performance subjected to different treatments. The beneficial role in growth and survival of leaf fish larva when fed with M.minuta is discussed.