CHEMICAL-COMPOSITION, RNA AND DNA CONTENTS, AND ALKALINE-PHOSPHATASE ACTIVITY WITH GROWTH OF STRIPED JACK LARVAE THROUGH JUVENILES

In order to obtain basic knowledge for promoting seed production of th e striped jack Caranx delicatissimus, chemical composition, nucleic ac id contents, and alkaline phosphatase activity (ALP) were measured in the fish, from larvae through juveniles at 1-3 day intervals. While re aring on rotifer, Artemia nauplii, and an artificial diet in that orde r, the total length of the fish increased satisfactorily from 2.8 mm i n the hatching larvae to 23 mm in the juveniles on day 42. Moisture de creased slightly throughout the rearing period. Crude protein and ash increased steeply until day 17, the morphological sifting point from l arvae to juvenile, but triglyceride and phospholipid temporarily fell in three periods of days 1-6, 14-16, and 24-28. DNA content and the RN A/DNA ratio respectively decreased and stepped up in periods of days 1 4-22 and days 34-42, except for steep increases by day 8. ALP increase d on days 3-6 and then maintained high levels until day 14. These indi cate that growth in the early life stages of striped jack is supported by cyclic phases of hyperplasia and hypertrophy while conducting quan titative and qualitative changes in body composition and enzymes as we ll as morphological development.