GUT ULTRASTRUCTURE AND DIGESTIVE PHYSIOLOGY OF TWO MARINE NEMATODES,CHROMADORINA GERMANICA(BÜTSCHLI, 1874) ANDDIPLOLAIMELLASP

Abstract

A comparative study was conducted of gut ultrastructure, ingestion and digestion of a variety of foods by 2 salt marsh nematodes: C. germanica and Diplolaimella sp. Diplolaimella sp. has a small, unarmored buccal cavity. It has a complex esophageal-intestinal valve that consists of muscle and gland-like cells. The intestinal cells are of 2 types: the anterior 4 cells are secretory and the remaining cells are absorptive. There are unusual microvilli lining the luminal borders of these cells that contain a cisterna along the central axis that is continuous with the cisterna of the endoplasmic reticulum. An unusual, structurally complex, fibrillar matrix lines the luminal cell borders. An amoeba is found residing in the intestinal lumen wherever food is present. C. germanica has a larger buccal cavity with 2 sets of 3 teeth. The intestine consists of secretory cells that are periodically sloughed off into the intestinal lumen. These cells have a variety of cell inclusions. The process of digestion was described for each species.