Ontogenetic Development of the Digestive System in Golden Pompano Trachinotus ovatus

The digestive ontogeny of Trachinotus ovatus from hatch to 32 days post-hatch was reviewed in this chapter. The development of digestive system in T. ovatus can be divided into three stages: stage I starting from hatching and ending at the onset exogenous feeding (3 DPH), stage II starting from first feeding and ending at the formation of gastric glands in fish stomach (15 DPH), and stage III starting from the appearance of gastric glands and continuing onward. The specific activity of lipase, trypsin, and amylase in fish increased rapidly from the exogenous feeding to 5–7 DPH and followed by random fluctuations. Pepsin activity was firstly detected on 15 DPH, and the specific activities increased with fish age. The dynamics of enzyme activity reflected the structural development in fish digestive system. After the formation of gastric glands in the fish stomach, the enzyme activities incline to be stable. According to the development of the digestive system, weaning of T. ovatus larvae can be initiated at 15 DPH. This chapter will improve our understanding of T. ovatus ontogeny during the larval phase and supply the feeding and weaning protocol for this important economic fish in hatcheries.