Developmental and Morphological Characteristics of Embryo, Larval,Juvenile, and Young Fish, Chromileptes altivelis

Abstract:

Artificial breeding of Chromileptes altivelis is difficult to marine fishing, and related studies on C. altivelis are limited. The present study investigated the embryonic and morphological development of larval, juvenile and young fish of C. altivelis using microscope, anatomical lens and digital camera. The morphological features and the time of development stages were described. The results showed that the embryonic development of C. altivelis was divided into five stages: cleavage stage, blastula stage, gastrula stage, neurula stage, and organogenesis stage. The embryonic development requires 27 h 25 min under the following condition in the sea water at 25−26℃ and salinity of 30. The post embryonic development of C. altivelis was divided into larval stage, juvenile stage and young fish stage based on the features of the yolk-sac, finfold, second dorsal fin spine, pelvic fin spine, scale, and body color. The larval stage was further classified into early larvae and late larvae based on the existence of the yolk-sac or not. The embryos developed into prelarvae in 2 days under water environment with temperature between 22 and 26℃, salinity between 29 and 31, DO≥5 mg/L. The yolk-sac of larvae disappeared and the postlarvae began at day 3. The larvae started to develop to juveniles at day 31. The juveniles completed metamorphosis and became young fish at day 57. The growth and configuration of the second spine of dorsal fin and the first spine of ventral fin were the most obvious changes during early development of C. altivelis. This study provides information for the propagation, seed culture and morphological identification of grouper fish.