The Anatomy of the Gastrointestinal Tract of the African Lungfish, Protopterus annectens
Article first published online: 13 APR 2010
Copyright © 2010 Wiley-Liss, Inc.
The Anatomical Record
Volume 293, Issue 7, pages 1146–1154, July 2010
How to Cite
Icardo, J. M., Wong, W. P., Colvee, E., Loong, A. M. and Ip, Y. K. (2010), The Anatomy of the Gastrointestinal Tract of the African Lungfish, Protopterus annectens. Anat Rec, 293: 1146–1154. doi: 10.1002/ar.21154
- Issue published online: 25 JUN 2010
- Article first published online: 13 APR 2010
- Manuscript Accepted: 11 FEB 2010
- Manuscript Received: 3 NOV 2009
- Ministerio de Educación y Ciencia, Spain. Grant Number: CGL2008-04559/BOS
- Protopterus annectens;
The gastrointestinal tract of the African lungfish Protopterus annectens is a composite, which includes the gut, the spleen, and the pancreas. The gut is formed by a short oesophagus, a longitudinal stomach, a pyloric valve, a spiraling intestine, and a cloaca. Coiling of the intestine begins dorsally below the pylorus, winding down to form six complete turns before ending into the cloaca. A reticular tissue of undisclosed nature accompanies the winding of the intestinal mucosa. The spleen is located along the right side of the stomach, overlapping the cranial end of the pancreas. The pancreas occupies the shallow area, which indicates on the gut dorsal side the beginning of the intestine coiling. In addition, up to 25 lymphatic-like nodes accompany the inner border of the spiral valve. The mesenteric artery forms a long axis for the intestine. All the components of the gastrointestinal tract are attached to each other by connective sheaths, and are wrapped by connective tissue, and by the serosa externally. We believe that several previous observations have been misinterpreted and that the anatomy of the lungfish gut is more similar among all the three lungfish genera than previously thought. Curiously, the gross anatomical organization is not modified during aestivation. We hypothesize that the absence of function is accompanied by structural modifications of the epithelium, and are currently investigating this possibility. Anat Rec 293:1146–1154, 2010. © 2010 Wiley-Liss, Inc.