Effects of diets and feeding rate on the survival and growth of Macquarie perch ( Macquaria australasica) larvae, a threatened Australian native fish

Abstract

Results of experiments on the influence of live food enrichment ( Artemia nauplii), stocking density and food concentration, and the effectiveness of dry diets on the rearing of yolk-sac resorbed larvae of the threatened Australian native fish Macquarie perch, are presented. Survival and growth, in length and weight, were significantly ( P < 0.05) enhanced when the larvae were fed enriched Artemia nauplii. Both stocking density and food concentration had an effect on larval survival and growth. At all stocking densities tested (2, 4, 8, 16 and 32 larvae l −1) larval survival increased with increasing initial food concentration, but larval length and weight were not influenced by an increase in food concentration from 1500 to 3000 of Artemia nauplii l −1 at stocking densities of 8, 16 and 32 larvae l −1. However, the best survival and growth was observed at the stocking density of 8 larvae l −1 and a food concentration of 3000 nauplii l −1. Macquarie perch larvae responded poorly when reared on dry diets alone, but a mixture of live food and dry diets in equal proportion resulted in improved survival and growth.