Influence of broodstock diets on growth, fecundity and spawning performance of swamp eel Monopterus albus

Abstract

Three experimental diets including frozen trash fish (Diet 1), the equal mixture of frozen trash fish and formulated pellets (Diet 2), and formulated pellets (Diet 3) were prepared and fed to the female broodstocks of Monopterus albus for 6 weeks. Swamp eels fed with Diet 3 exhibited lower values of weight gain and specific growth rate (p < 0.05). Plasma concentrations of total protein, total cholesterol and estradiol were higher in fish fed Diet 1. Fish fed with Diet 3 had higher values of crude protein (CP) and ash, together with lower moisture concentration in muscle. Concentrations tendency of CP, ash and moisture in the ovary were completely opposite to that in the muscle. The concentration of total n−3 fatty acids was highest in both the muscle and ovary of fish fed Diet 1. Fertilization of eggs in fish fed Diet 3 was blocked. It suggested that the insufficiency of plasma estradiol, and n−3 fatty acids in the muscle and ovary, together with the impediment of protein mobilization from muscle to ovary, caused the fertilization failure of M. albus fed with formulated feeds. Equal mixture of trash fish and formulated pellets was appropriate for the successful propagation of swamp eels.