Abstract:Scale morphology, growth and squamation chronology were described for the Schizothorax davidi reared in the laboratory. The results showed that the onset and completion of scale formation occurred at 62 and 110 days post hatching (dph), respectively, and the scale appearance was related to age. The onset of six locations of scale development, which were the lateral line near the posterior border of gill cover, the lateral line near the middle of caudal peduncle, the base of anal fin, the base of pelvic fin, the base of dorsal fin, and isthmus, occurred at 62, 71, 79, 83, 91 and 104 dph, respectively. Furthermore, the results of the histological observation revealed that five steps can be distinguished in the scale formation and development: early morphogenesis, late morphogenesis, early differentiation, late differentiation and scale fold. In addition, the pattern of scale formation may be useful in enhancing understanding of systematics, functional morphology and habitat use.