Osteological development and anomalies in larval stage of hatchery-reared yellow catfish Pelteobagrus fulvidraco

Comprehensive knowledge of osteological development of fish not only provides means for understanding its functional development, but also allows early detection of skeletal anomalies. The present study was conducted to determine osteological development and occurrence of anomalies from the first to the 40th day after hatching (DAH) for yellow catfish Pelteobagrus fulvidraco, a commercially important species in China. Vertebral ontogeny started with formation of anterior neural arches at 3 DAH, and completed at 6 DAH. Vertebral centra started to develop at 4 DAH and ossification in all centra was visible at 15 DAH. Caudal fin appeared at 2 DAH and ossification was visible at 26 DAH. The onset of dorsal and anal fins appeared at 4 DAH and their ossifications were visible at 20 DAH. Pectoral fins were present before first feeding and formed entirely at 9 DAH, and their ossifications were visible at 21 DAH. Pelvic fins appeared at 9 DAH, and formed completely at 21 DAH. The ossification of pelvic fins was not finished until the end of the experiment (40 DAH). 24 types of skeletal anomalies were observed. About 20% of individuals showed at least one anomaly. Haemal vertebrae anomalies occurred at the highest frequency, followed by pre‐haemal, caudal vertebrae and anal fin anomalies, and caudal fin had the lowest anomalies frequency. For the first time, our study determined osteological development and anomalies incidence in larval yellow catfish, which help further investigations into rearing conditions leading to appearance of these anomalies to prevent their incidence.