EFFECTS OF DIETS AND FEEDING RATE ON THE SURVIVAL AND GROWTH OF MACQUARIE PERCH (MACQUARIA-AUSTRALASICA) LARVAE, A THREATENED AUSTRALIAN NATIVE FISH

Results of experiments on the influence of live food enrichment (Artem ia nauplii), stocking density and food concentration, and the effectiv eness of dry diets on the rearing of yolk-sac resorbed larvae of the t hreatened Australian native fish Macquarie perch, are presented. Survi val and growth, in length and weight, were significantly (P < 0.05) en hanced when the larvae were fed enriched Artemia nauplii. Both stockin g 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 concentrat ion, but larval length and weight were not influenced by an increase i n food concentration from 1500 to 3000 of Artemia nauplii l(-1) at sto cking densities of 8, 16 and 32 larvae l(-1). However, the best surviv al and growth was observed at the stocking density of 8 larvae l(-1) a nd 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. (C) 1997 Elsevier Science B.V.