Feeding live or frozen Moina macrocopa (Strauss) to Asian sea bass, Lates calcarifer (Bloch), larvae

Abstract

Growth and survival of hatchery-reared sea bass, Lates calcarifer, larvae fed live or frozen Moina macrocopa were determined, In Experiment 1, Moina was fed to sea bass of different sizes: 3.6 mm, 5.5 mm and 7.6 mm standard length (SL) at stocking. After 15 days of rearing, fish with a mean initial SL of 3.6 mm had the highest specific growth rate (SGR, 18.82% per day). However, the mean survival rate was higher for fish with a mean initial size of 5.5 mm (64.76%). The mean number of ingested Moina increased with the fish body size and with the length of the feeding period. In a separate trial, sea bass larvae, regardless of size, ingested equal numbers of Artemia and Moina. In Experiment 2, live or frozen Moina was used as feed for 20-day sea bass fry (8.3 mm Sl and 13.4 mg) and compared to minced fish-by-catch (control). SGR and survival were significantly higher for fish fed live Moina. Sea bass fed frozen Moina and minced fish-by-catch had comparable growth and survival rates. Results showed that for hatchery rearing of sea bass, feeding Moina can effectively reduce the use of expensive Artemia. However, fry survival can be optimized by feeding live Moina to fish with a mean initial size of 5.5 mm SL.