THE WISENT (BISON-BONASUS, BOVIDAE) AS AN INTERMEDIATE HOST OF 3 SARCOCYSTIS SPECIES (APICOMPLEXA, SARCOCYSTIDAE) OF CATTLE

Sarcocysts were found in muscle tissue of a wisent (Bison bonasus) whi ch was born and kept in Germany. Light microscopic and TEM examination revealed all the three named species known froin cattle: Sarcocystis cruzi (,,thin-walled'', with longer hair-like villar protrusions of th e primary cyst wall); S. hirsuta (,,thick-walled'', with tongue-like p rotrusions of the cyst wall arising with very short and narrow stalkle ts from the surface of the cyst and containing rows of electron-dense granules in the core); and S. hominis (,,thick-walled'', with finger-l ike protrusions of the cyst wall Dot constricted al their base and con taining few or no electron-dense granules). So far, only S. cruzi was known to occur in Bison bison in North America. The findings in the wi sent strikingly support a modified conception of the intermediate host specificity in Bovinae. In this connection the identity of S. cruzi a nd S. poephagicanis is suggested as well as that of S. hirsuta and S. poephagi.