Esophagogastric region and liver tissue in dog-faced water snake Cerberus rynchops : Histology and histochemistry

Observation of the esophagogastric region and liver tissue of the dog-faced water snake, Cerberus rynchops, living in Thailand was evaluated using standard histological techniques. The results revealed that the digestive tract of this snake consists of three parts: the oesophagus, stomach and intestine, respectively. From the histological analysis, the longitudinal folds of the oesophagus were lined by pseudostratified columnar epithelia with goblet cells. The goblet cells stained positively with periodic acid-Schiff (PAS) and alcian blue (AB) methods. In the stomach, gastric glands extended into the lamina propria. Each gastric gland had a greater cell size than other regions and also a branched tubular gland was visible in the histological images. The mucous neck cell was positive to PAS and AB reactions, whereas, the oxynticopeptic cells slightly reacted to both PAS and AB staining and were preferentially located in this gland. The liver parenchyma of C. rynchops was composed of hepatic sinusoids and hepatocytes. In conclusion, this was the first study on digestive tract and liver tissue in C. rynchops from the Paknam Pranburi Estuary, Thailand.