Gut Associated Lymphoid Tissue in the Dogfish Scyliorhinus Canicula: A Light Microscopic Study

Abstract

The alimentary tract of the common dogfish, Scyliorhinus canicula L. was examined for the presence of gut associated lymphoid tissue (GALT). GALT was present in the buccal cavity, oesophagus, pyloric stomach, intestine containing the spiral valve, rectum and cloaca, but absent from the cardiac stomach. In the intestine containing the spiral valve the highest levels of GALT were recorded. The GALT occupied three tissue niches: as individual leucocytes in the lamina propria as accumulations in the lamina propria and as individual leucocytes in the ephithelium. Four leucocyte types were identified lymphocytes, granular cells, macrophages and plasma cells. The presence of lymphoid tissue at such high levels in the gut suggests it has a potentially important immunological function.