This photomicrograph revealed some of the ultrastructural morphology exhibited by an adult cestode, Echinococcus granulosus
, which had been found in a dog. E. granulosus
causes what is known as cystic echinococcosis. As dogs and other canids are the only definitive hosts for Echinococcus
, adults are not expected to be found in the human host. Adults range from 3mm - 6mm in length and usually consist of a scolex, and three proglottids. The third (terminal) proglottid is gravid, and is longer than wide, as can be seen in this instance. The scolex contains four suckers and a rostellum with 25 - 50 hooks.