Scanning electron microscopy of Ancylostoma ceylanicum and its site of attachment to the small intestinal mucosa of the dog.

The relationship between the hookworm Ancylostoma ceylanicum and the host intestinal mucosa in situ has been examined by using an in vivo fixation technique and scanning electron microscopy. Heads of the adult worms were buried deeply in the mucosa of the dog's small bowel. At some sites of attachment there was severe atrophy and ulceration of the immediately surrounding villi. Superficial deposits of fibrillar material with many enmeshed erythrocytes were associated with these attachment sites. When adult worms became removed after fixation, large numbers of erythrocytes could be seen at the base of the ulcers. Examination of the morphological details of adult A. ceylanicum revealed the characteristic mouthparts of large outer ventral teeth and smaller inner teeth. The distance between adjacent transverse cuticular striations was measured as 5.2 microns. The wide separation of the externolateral ray from the closely related mediolateral and posterolateral rays was illustrated together with the functi characteristic mouthparts of large outer ventral teeth and smaller inner teeth. The distance between adjacent transverse cuticular striations was measured as 5.2 microns. The wide separation of the externolateral ray from the closely related mediolateral and posterolateral rays was illustrated together with the functi characteristic mouthparts of large outer ventral teeth and smaller inner teeth. The distance between adjacent transverse cuticular striations was measured as 5.2 microns. The wide separation of the externolateral ray from the closely related mediolateral and posterolateral rays was illustrated together with the functional relationship of male and female copulating worms.