NATURAL SPAWNING AND MASS LARVICULTURE OF BLACK PORGY ACANTHOPAGRUS-SCHLEGELI IN CAPTIVITY IN TAIWAN

The black porgy Acanthopagrus schlegeli is one of the most important m arine fish cultured in Taiwan. Wild-caught broodstock were spawned nat urally in captivity at water temperatures of 19-26 C in 1989 and 1990. Females produced 352,000 to 957,000 eggs per female during the spawni ng period. The hatched larvae were reared in 45-m(3) rectangular cemen t tanks and fed initially on rotifers, Brachionus plicatilis, followed by Artemia nauplii, and finally weaned onto an artificial diet. Larvi culture trials to 40 d produced juveniles of 13.1-14.2 mm average tota l length, at a survival rate ranging from 18.3 to 74.8%. Lordotic defo rmation was observed in the juvenile stage. However, when an oil skimm er was used to remove the oil film on the water surface, the incidence of lordosis was reduced from 14.4 to 6.1%. High mortality of the larv ae occurred during the initial 10-15 d after hatching and cannibalism was observed when larvae reached 7 mm total length. Juveniles grew to size of 83.7-101.4 mm total length with survival rate of 27.9-28.2% in 100 d. The results indicate that the present technique can be used fo r mass seed production of black porgy.