Growth Performance of Japanese Sea Bass (Lateolabrax japonicus) in 8-m3 Cages with Soymeal- and Fishmeal-based Feeds
Category Aquaculture Saltwater Sea Bass
Region Northeast Asia
Japanese sea bass (Lateolabrax japonicus) growth in cages was evaluated from small fingerling to market size during the 1999 and 2000 production seasons at Nan Ji Island along the east coast of China. Growth from fingerling to sub-market size was evaluated in 1999 with soymeal-based and fishmeal-based feed rations formulated to contain 43% protein and 12% fat, and from sub-market to market size in 2000 with the 43/12 soymeal-based feed ration. The soymeal- and fishmeal-based rations were formulated to be isonitrogenous and isocaloric and were fed in an extruded pellet form. In June 1999, fish were stocked in 8.0-m3 cages at 350 fish per m3 and fed for 153 days. Sea bass grew from 3 g to 297g with the soymeal-based ration, and from 3 g to 289 g with the fishmeal-based ration. There was no significant difference (P>0.05) in fish growth or feed conversion efficiency with the two feeds. FCR averaged 1.53:1 and 1.55:1 for the soymeal- and fishmeal-based rations, respectively. Survival averaged 50% for all cages and treatments. The sea bass were over-wintered and restocked in 8.0-m3 cages at 175 fish per m3 in late April 2000. Sea bass grew from 302 g to 527 g in 90 days on the soymeal-based ration, with an average FCR of 1.54:1. Fish survival averaged 93%. Gross fish production averaged 85.9 kg/m3. Net profit was RMB 28,559 for the three trial cages, or RMB 1,190/m3, at an August 2000 market price of RMB 36/kg.