Abstract: The body color variation and fins development at early life stages of Trachinotus ovatus were continuously observed by colleting samples of larvae, juveniles and young fish reared in pond from newly hatching to 31 days after hatching (DAH) under water temperature of 24.73 ± 2.11 ℃ , salinity of 20 ‰ - 24 ‰ and pH of 8.0 - 8.2 . The newly hatched larvae were covered by melanin . Brown pigment in eye-sport increased at 2 DAH, while the mouth was not found opening and visual sense undeveloped. Mouth opened at 3 DAH, eye became black, big and protruding, covered by melanin, with optic function. Metamorphosis occurred at 17 DAH, when the larvae were turned into juveniles and the body became opaque. The body color changed into brown at 22 DAH while the metamorphosis was finished from juvenile to young fish. It was argent a t 30 DAH with the body color in accord with adult stage. The fin development was in order of pectoral fin, caudal fin, dorsal fin, anal fin and ventral fin. Primordial pectoral fin appeared in 1-day-old larvae, first feeding was observed at 2 - 3 DAH, with the fan-like pectoral fin. Fins were developed completely at 17 DAH , symbolizing the start of juvenile stage. Results of this research indicated that body color variation and fins development in T. ovatus played a very important role to life activities of larvae and juveniles such as feeding, behavior, movement, growth, metamorphosis and survivorship, being one of the important characters in metamorphosis development of larvae and juveniles, it correlated closely with artificial seedling production especially in feeding and grading.

Key words: Trachinotus ovatus , early development, body colors variation, fins development