The stomach of the harbor porpoise Phocoena phocoena (L.).

Abstract

The morphological and cytological characteristics of the stomach of the harbor porpoise (Phocoena phocoena (L.)) are described from dissections and histological preparations. The stomach consists of the following three compartments: forestomach, with keratinized stratified squamous epithelium and well-developed muscularis externa; main stomach, with rugose mucosa containing mucous, parietal, and zymogenic cells; and pyloric stomach, with typical pyloric glands. The opening from the fore-stomach to the main stomach is located near the esophageal opening. A sphincter is not present, but the opening is surrounded by several epithelial folds. The main stomach is joined to the pyloric stomach by a narrow connecting channel possessing pyloric glands. The gross and microscopic characteristics of the compartments are interpreted in relation to function.