Larval and juvenile development of yellowtail reared in the laboratoty.

Abstract

Morphological development of early life stages in laboratory-reared yellowtail was observed and reported with special reference to fin development, pigmentation and squamation. The specimens were obtained serially by experimental rearing from eggs to larvae, measuring 3.5mm in standard length (SL) at hatching and to young (about 70mm SL). Larval development and squamation were illustrated. The transition from post-larvae to juveniles occurred between 9.85 to 13.5mm SL. Squamation began in larvae 22.1mm SL and was completed when thelarvae attained 40.2mm SL. Larval growth during initial 40 days was expressed by the equation SL=3.27e0.048x, where SL=standard length, and X=days after hatching. Some implications in morphological development of external and internal characters was discussed for better under-standing the early life stages of Seriola quinqueradiata.