A closed system was designed for mass culture of marine finfish larvae. Southern sea bass (Centropristis melana) brood stock were collected in the Gulf of Mexico during January‐March, 1975, their natural spawning season. Brood stock were maintained in a simulated spawning environment of 17–19 C temperature and 10 hr L:14 hr D photo‐period. Vitellogenesis of ovarian oocytes remained in the tertiary yolk globule stage in females held under these conditions and males would release milt freely upon manual stimulation. Final oocyte maturation and spawning were induced with Human Chorionic Gonadotropin and manual spawning techniques. Approximately 2,500 larvae were reared in three trials using 2,000–liter silo tanks with biological filtration. Laboratory reared rotifers (Brachionus plicatilis) were solely used as food the first 4 days after feeding began. Wild plankton, rotifers, Artemia nauplii, and prepared flake were also used as larvae developed. Greatest larval survival from hatching was 10.0%. Larvae grew from 2.78 mm to 9.0 mm in 24 days; the greatest growth rate occurred after day 14. Physiological edema was observed in two trials affecting 30–50% of the larvae. Physiological edema appears to be the principal constraint to successful rearing of sea bass larvae.

Vitellogenesis, culminating in spawning, was artificially induced in red drum (Sciaenops ocellata) using photoperiod and temperature as exogenous stimuli. Maturation was induced out of season during the normal refractory period of red drum found in central Florida waters. Four regimes were compared to a control. Three regimes culminated in advanced vitellogenesis and spawning. A semi‐natural regime induced spawning in 129 days, an abbreviated decelerating regime induced spawning in 83 days, and an abbreviated accelerating/decelerating regime induced spawning in 117 days. Functional maturity of females was defined by analysis of vitellogenic stage frequency and oocyte diameter frequency. Ovarian biopsies were taken by catheter at 30‐day intervals during experiment I, and 60‐day intervals during experiment II. For a 90‐day period in 1976, 4 females spawned 8.43 million eggs. For a 100‐day period in 1977, 8 females spawned 4.41 million eggs. Fertilization success was always greater than 99% and mean hatching success was 93.40% for all spawns.

Laboratory‐reared juvenile southern sea bass, Centropristis melana (Ginsberg), were studied to evaluate effects of five diets on growth and food conversion. Diets studied were Marine Ration 20, squid, Marine Ration 30, Catfish Cage Chow, and Trout Chow; each diet had a different total protein content. Diet treatments were conducted using a completely random design in 2.36 times 0.97 times 0.50 m tanks with biological filtration. Fish were fed twice daily at 3% body weight day‐1 and reduced to 2% body weight at the first signs of wastage. Body weights and total lengths were recorded every two weeks. The Marine Ration 20 diet was terminated at sampling period I due to diet rejection and high mortalities. Significant differences (= 0.05) in mean body weights among remaining diets occurred by the eighth week, as demonstrated by Tukey's Honestly Significant Difference test. The experiment was terminated after ten weeks. Of all diet treatments taken to termination, juveniles fed squid suffered the highest number of mortalities. Food conversion (g feed g‐1 gain) and mean percent body weight increase for Trout Chow, squid, Catfish Cage Chow, and Marine Ration 30 were 1.30 and 172.90%, 1.55 and 180.57%, 2.48 and 63.10%, and 3.55 and 36.00%, respectively. Results of all measured parameters show that Trout Chow was superior in rearing juvenile southern sea bass.