A PRELIMINARY-STUDY ON THE GROWTH-PERFORMANCE OF JUVENILE RED GROUPERREARED IN A RECIRCULATING-WATER SYSTEM

Growth, feed consumption, and survival were evaluated for young red gr ouper Epinephelus morio reared in a recirculating-water system over 28 3 d. This fish-holding system was chosen because of site constraints a nd scarcity of seawater. Red grouper were size-graded into four experi mental groups and fed chopped frozen clupeids. Water quality was monit ored weekly. Daily growth rates of 0.48-0.69 g/fish were lower than th ose for other grouper species cultured in tanks or floating net cages. Survival ranged from 93.3 to 93.7% for three of the size-groups. Dail y feed consumption rates progressively declined during the trial from 3.1-4.7% to 0.9-1.0% of body weight. Some pathological syn dromes, suc h as exophthalmia and abdominal distension, appeared after day 283, re sulting in high mortalities in all size-groups. Deaths were probably d ue to low dissolved oxygen (3.9-4.7 mg/L) during the last 39 d of the grow-out trial. Further studies are needed before the feasibility of r ed grouper culture can be adequately as-certained.