A Preliminary Study on the Growth Performance of Juvenile Red Grouper Reared in a Recirculating-Water System

Growth. feed consumption, and survival were evaluated for young red grouper Epinephelus morio reared in a recirculating-water system over 283 d. This fish-holding system was chosen because of site constraints and scarcity of seawater. Red grouper were size-graded into four experimental groups and fed chopped frozen clupeids. Water quality was monitored weekly. Daily growth rates of 0.48–0.69 g/fish were lower than those 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. Daily feed consumption rates progressively declined during the trial from 3.1–4.7% to 0.9–1.0% of body weight. Some pathological syndromes, such as exophthalmia and abdominal distension, appeared after day 283, resulting in high mortalities in all size-groups. Deaths were probably due 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 red grouper culture can be adequately ascertained.