Redescription, deposition of life-cycle stage specimens ofHeydorn, Gestrich, Mehlhorn and Rommel, 1975, and amendment toMoulé, 1888.

Abstract

There is considerable debate concerning the life cycles and taxonomy ofspecies in cattle. Of the 8 species ofnamed from cattle, 2 (and) are morphologically distinctive because their sarcocysts are microscopic and the sarcocyst wall is thin (<0.5m thick). The sarcocysts of the remaining species (,,,,,) have thick (5&#x2013;8m) walls indistinguishable by light microscopy, alone. To provide needed clarity, I herein review the history, nomenclature and life cycle of(originally named by Heydorn and associates from Germany), redescribe it and deposit specimens of its various life-cycle stages at a museum for future reference. I also provide means to distinguish this parasite from. Cats are the definitive hosts for bothand. The sarcocysts ofare microscopic, its sarcocyst wall is type 10g, it has 2 schizogonic stages in blood vessels and sarcocysts are formed between 25 and 30 days post-inoculation in striated muscles, but not in the heart. Sporulated oocysts are 17.1 &#xd7; 12.7m and sporocysts are 12.8 &#xd7; 8.4m. The sarcocysts ofare macroscopic, up to 7 mm long, its wall is type 18. Nothing is known of the development ofin cattle tissues and in cat intestine. Size of its oocysts and sporocysts is uncertain.