A study of morphology and histology of the alimentary tract of Glyptosternum maculatum (Sisoridae, Siluriformes)

Xiong, D., Zhang, L., Yu, H., Xie, C., Kong, Y., Zeng, Y., Huo, B. and Liu, Z. 2011. A study of morphology and histology of the alimentary tract of Glyptosternum maculatum (Sisoridae, Siluriformes). - Acta Zoologica (Stockholm) 92: 161-169. The structure of alimentary tract has been studied in a cold water fish Glyptosternum maculatum, an endemic teleost species of notable economic importance and with high potential for controlled rearing of the species in Tibet, by light and electron microscope. Glyptosternum maculatum has short oesophagus, large caecal-type stomach and short intestine, and the digestive tract with four layers: mucosa, submucosa, muscularis and serosa. Taste buds were found in the epithelium of lips, buccopharynx and oesophagus. The stratified epithelium of buccopharynx and oesophagus was located with numerous goblet cells. The U-shaped stomach has three parts, corresponding to mammalian cardiac, fundus and pyloric portion, lined with a single-layered columnar epithelium, and tubular gastric glands are present in cardiac and fundic portion, but absent in pyloric portion. No pyloric caeca was detected. The intestine is separated from the stomach by a loop valve. The intestine epithelium is composed of simple columnar cells with a distinct microvillus brush border and many goblet cells. Meanwhile, the intestinal coefficient was 0.898. At the ultrastuctural level, three type cells (mucous, glandular and endocrine cell) were found in the stomach, and glandular cell with a great amount of pepsinogen granules. The enterocytes of the intestinal mucosa display abundant endoplasmic reticulum, mitochondria and well-developed microvilli. Congxin Xie, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, China. E-mail: xiecongxin@mail.hzau.edu.cn or dreamsail_2005@yahoo.com.cn.