Effects of rotifer density (Brachionus plicatilis) on growth and survival rate of pearl grouper at the nursery stage from fry to 18 days old

Abstract

The rotifer Brachionus plicatilis plays a crucial role as live feed in the cultivation of marine fish larvae. Different fish species, however, require different densities of rotifers during rearing. A study was conducted to determine the optimal rotifer density for the growth and survival rate of the pearl grouper (hybrid grouper) larvae from the fry stage to 18 days old, with four feeding treatments of 4 densities of rotifer: 10, 15, 20 or 25 rotifers/mL. Each treatment was performed in triplicate. The experiment was terminated when the fish larvae began consuming Artemia. The results indicated that the growth and survival rate of the pearl grouper were highest, and the rate of deformities and coefficient of variation (CV) in body length were lowest when reared from the fry stage to the fingerling stage at 18 days old with a rotifer density of 20 individuals/mL.