Larval intervals of the sea bass, Lates calcarifer, based on the development of swimming and feeding functions.

Abstract

Developmental sequences of characters concerned in swimming and feeding function were examined on laboratory-reared seabass larvae. Based on a scheme of development events constructed in this study, the early life hisory of the species can be divided into the following five phases. A (to about 2.5 mm TL): larvae have no noticeable skeletal structure concerned in swimming and feeding function. B (to about 4.5 mm TL): principal elements of swimming-related characters appear and start to develop; jaw and pharyngeal teeth strt to develop. C (to about 6.0 mm TL): position of the greatest body depth begins to shift bacward; dorsal and anal fin-rays attain to adult commplements; serration-like upper jaw teeth decrease in number and finally disappear. D (to 7.0 - 7.5 mm TL): notochord end flection is completed; conical spper jaw teeth start to develop, replacing the serration-like teeth. E (beyond 7.0 - 7.5 mmTL): larvae can be regarded as reaching juvenile stage in this phase from the view-point of functional morphology, although the first larvae with completely develop fin-ray counts was 10.25 mm TL in this study.