Histopathological Effects of the Acanthocephalan Leptorhynchoides thecatus in the Ceca of the Green Sunfish, Lepomis cyanellus

• Published in: Transactions of the American Microscopical Society 1994-04, Vol.113 (2), p.161-168
• Main Authors: de Buron, Isaure, Nickol, Brent B.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cecum; Fish; Goblets; Infectious diseases; Intestines; Lymphocytes; Medical sciences; Miscellaneous; Mucosa; Parasite hosts; Parasites; Parasitic diseases; Parasitism; Proboscis
• ISSN: 0003-0023; 2325-5145
• DOI: 10.2307/3226644

Green sunfish (Lepomis cyanellus) possess an alimentary canal that has seven pyloric ceca, some or all of which may be parasitized by the acanthocephalan Leptorhynchoides thecatus. The microscopic anatomy of ceca with worms and the microscopic anatomy of ceca without worms in parasitized fish were compared to each other and to that of ceca from unparasitized fish. Parasites occluded ceca and caused significant distention (two-tailed Student's t-test, P < 0.05). Frequently, the proboscis was positioned in the lamina propria, but sometimes attachment was in the muscularis mucosa. Occasionally, the cecal wall was perforated. Epithelium was destroyed at the site of attachment and cell debris occurred in the lumen. The abundance of goblet cells in the mucosa of infected ceca was significantly greater than in ceca without worms whether in parasitized or unparasitized fish. Circular and longitudinal muscle layers in the muscularis mucosa were significantly thicker in parasitized than in unparasitized ceca. Additionally, muscle layers in unparasitized ceca of infected fish were significantly thicker than those in uninfected fish, revealing an effect of parasitism more general than necrosis at the site of attachment.