A study on the histology of digestive system in early life stages of Oplegnathus fasciatus

Objective The histology of digestive system in early life stages of Oplegnathus fasciatus was investigated.

Method By using continual section cutting technique, morphological changes and histological characters from newly hatched larvae to 35 days after hatching were described.

Result and conclusion Under the conditions of water temperature 24-27 ℃, salinity 29-30 and pH 7.4-8.2, the digestive tract of newly hatched larvae was only an undifferentiated simple closed tube above the posterior segment of yolk-sac with larger volume and color in reddish by H-E staining. Digestive system of O. fasciatus developed their morphology and function further with growth; it can be divided three stages: digestive tract hardly differentiated at the first stage from 0 to 3 days after hatching. At the second stage from 4 to 18 days after hatching, the digestive system was brought to primarily perfect, functioning as feeding, digestion and assimilation. At the third stage from 19-35 days after hatching, gastric glands and pyloric caeca were formed and development of digestive system became perfect and similar to that of the adult fish.