Tissue damage in the naturally infected intestine of the popular edible fish Parastromateus niger by the acanthocephalan parasite Serrasentis niger Bilqees, 1972 is described here based on original research. This infection caused considerable tissue damage. Penetration of the spiny proboscis of the parasite resulted into perforation of intestine wall and severe tissue reactions. Microscopic examination of the histology sections of infected intestine revealed destruction of all layers of intestinal wall. Degeneration of mucosa with necrosis was a common finding. Intestinal mucosa was...