Intensive culture and use of marine copepod Paracalanus parvus (Claus) for larval rearing of Asian seabass Lates calcarifer (Bloch)

Abstract

The marine copepods are being a nutritionally superior live feeds for commercially important cultivable fish species, as they are a valuable source of protein, essential amino acids, lipid and highly unsaturated fatty acids (20:5 n-3 and 22:6 n-3) which are essential for larval survival and growth. In addition, the growth stages of copepods from first nauplius to adult provide a broad spectrum of prey sizes. This makes them suitable prey for a similarly broad range of developing fish sizes. Based on these facts, the marine copepod Paracalanus parvus (Claus) (Paracalanidae) was cultured in high density at low volume of seawater in our laboratory to feed the larvae of Asian seabass Lates calcarifer (Bloch) (Perciformes, Latidae). The copepod species exhibited excellent population producing 1,88,117 nos. L-1 comprising 94807 nauplii, 65499 copepodites and 27811 adults L-1 fed with mixed microalgae diets viz., Chlorella marina, Isochrysis galbana, Dunaliella salina and Nannochloropsis sp. The cultured copepods were harvested and used as feed for larviculture of L. calcarifer. The seabass larvae with an average initial length of 10.66±2.08 mm and weight of 23.33 mg were stocked at 2 nos. L-1 of seawater. The larvae were fed with copepods at the rate of 5 nos. ml-1 for three times a day. The copepods fed L. calcarifer larvae showed tremendous growth (44.33±2.08 mm body length and 338±8.19 mg Wt.) and high survival (93±:6 n-3) which are essential for larval survival and growth. In addition, the growth stages of copepods from first nauplius to adult provide a broad spectrum of prey sizes. This makes them suitable prey for a similarly broad range of developing fish sizes. Based on these facts, the marine copepod Paracalanus parvus (Claus) (Paracalanidae) was cultured in high density at low volume of seawater in our laboratory to feed the larvae of Asian seabass Lates calcarifer (Bloch) (Perciformes, Latidae). The copepod species exhibited excellent population producing 1,88,117 nos. L-1 comprising 94807 nauplii, 65499 copepodites and 27811 adults L-1 fed with mixed microalgae diets viz., Chlorella marina, Isochrysis galbana, Dunaliella salina and Nannochloropsis sp. The cultured copepods were harvested and used as feed for larviculture of L. calcarifer. The seabass larvae with an average initial length of 10.66±2.08 mm and weight of 23.33 mg were stocked at 2 nos. L-1 of seawater. The larvae were fed with copepods at the rate of 5 nos. ml-1 for three times a day. The copepods fed L. calcarifer larvae showed tremendous growth (44.33±2.08 mm body length and 338±8.19 mg Wt.) and high survival (93±