A REVISION OF THE SPECIES OF BOTHRIOCEPHALUS RUDOLPHI, 1808 (CESTODA,PSEUDOPHYLLIDEA) PARASITIC IN AMERICAN FRESH-WATER FISHES

The species of the pseudophyllidean genus Bothriocephalus Rudolphi, 18 08 parasitising freshwater fishes in America are revised, based on the examination of type and voucher specimens of seven taxa. There are fi ve valid species: Bothriocephalus claviceps (Goeze, 1782), B. cuspidat us Cooper, 1917, B. formosus Mueller & Van Cleave, 1932, B. acheilogna thi Yamaguti, 1934, and B. pearsei Scholz, Vargas-Vazquez & Moravec, 1 996. B. texomensis Self, 1954 from Hiodon alosoides in the USA, and B. musculosus Baer, 1937 from a cichlid Cichlasoma biocellatum (= C. oct ofasciatum) which died in an aquarium in Switzerland, are synonymised with B., cuspidatus. B. schilbeodis Cheng & James, 1960 from Schilbeod es insignis in the USA, B. speciosus (Leidy, 1858) Leidy, 1872 from Bo leostoma olmstedi in the USA, and B. cestus Leidy, 1885 from Salvelinu s sp. in Canada are considered to be species inquirendae until new mat erial for the evaluation of their taxonomic status is available. B. co rdiceps (Leidy, 1872) from Salmo (= Salvelinus)fontinalis in North Ame rica is in fact a larva (plerocercoid) of a Diphyllobothrium species. The study showed that there have been many misidentifications, mostly of B. cuspidatus erroneously designated as B. formosus or B. claviceps . The five valid species are redescribed and illustrated, with emphasi s on scolex morphology. The distribution of individual taxa and the sp ectrum of their definitive hosts are briefly reviewed and a key facili tating identification of individual species is also provided.