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DOI: 10.4322/jms.016013
Histomorphology of digestive tract in two closely related mountain newts (Salamandridae: Neurergus kaiseri and Neurergus microspilotus)
Publication History
10 June 2014
22 February 2016
Publication Date:
10 October 2018 (online)
Abstract
Introduction: The digestive system of vertebrates presents various structural and functional adaptations to their diverse feeding habits. Material and methods: Anatomical, histological and histochemical examinations were made from digestive tract in two closely related mountain newts (Salamandridae: Neurergus mierospilotus and Neurergus kaiseri). Sections were stained with Hematoxylin and Eosin, Periodic Acid SchifPs and Alcian Blue. Results: In both species the pharynx and esophagus are covered by psudostratified ciliated columnar epithelium with goblet cell which is positive with PAS and AB. The stomach in N. kaiseri and N. mierospilotus is a straight, expanded conical tube, laying slightly to the left side of the body cavity, and terminating at the pylorus. The stomach is divided into three distinct parts, the cardia, fundus and pylorus. Although in both species the epithelium of the stomach surface and of the lining of the crypts consists of a single layer of high columnar cell, but the apical portion of the cells in N.kaiseri consists of homogeneous acidophilic granules while in N.mierospilotus is foamy. The duodenum is short and is sharply reflexed along the medial aspect of the stomach. Duodenum in N. kaiseri and N. mierospilotus shows villi which consists of the epithelial covering and a core of connective tissue containing blood and lymph capillaries. The large intestine in both N. kaiseri and N. mierospilotus is located along the median line. The intestine is a coiled tube of a regular diameter, larger than, that of the duodenum. Histologically, these are no villi in large intestine and goblet cells rise to numerous. The epithelium is simple columnar, and the lamina propria and submocosa are strongly reduced. Conclusion: The findings of this study demonstrate that the morphological description of the digestive tract of N. kaiseri and N. mierospilotus are very similar and can be extended to the other newts.