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Histological Study of the Digestive System Organogenesis for the Mandarin Fish, Siniperca chuatsi
WU, Xue-feng; ZHAO, Jin-liang; QIAN, Ye-zhou & WU, Chao
Abstract
The development of the digestive tract and accessory glands in the Mandarin fish (Siniperca chuatsi)
larvae from hatching to 35 days after hatch (DAH) was morphologically and histologically examined using light
microscopy. Hatched at the temperature varying from 18.0 to 20.0°C, the digestive tract of the newly hatched larva of the
mandarin fish was a simple closed tube under the notochord and above the posterior segment of the oval yolk sac
containing the oil globule. On 2 DAH, the mouth and the anus were opened, the digestive tract run through. On 4 DAH,
the epithelium of the digestive tract was differentiated, the live and pancreas appeared, and fish began to turn endogenous
feeding to exogenous feeding. On 5 DAH, the larvae begun to ingest exogenous food, the digestive tract was
differentiated into five portions: buccopharyngeal cavity, esophagus, stomach, anterior and posterior intestine. The yolk
was gradually absorbed and disappeared on 9 DAH. During the following developmental period of the larvae, the
structure and function of the digestive system became mature gradually. Infranuclear vacuoles occurred in the anterior
intestine on 7 DAH and esoinophilic granulae occurred in the posterior intestine on 8 DAH, which indicates the start of
lipid and protein absorption. Gastric glands were observed on 13 DAH, which indicates the passage through the juvenile
period.
Keywords
Siniperca chuatsi; Digestive system; Organogenesis; Histology; Morphology
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