Comparative Studies on Trematodes Gyrodactyloidea) from the Gills of North American Freshwater Fishes

Abstract

Bibliography 65 Plates taxonomic categories, the described species of North American freshwater Gyrodactyloidea now total sixty-one. Three of these, namely, Tetraonchus mo?ienteron(Wa.gener, 1857) , Dactylogyrus anclioratus (Dujardin, 1845), and Gyrodactylus elegans von Nordmann, 1832, were first described from another continent (Europe). Seven of these belong to the Gyrodactylinae (genus Gyrodactylus) , six to the Dactylogyrinae (genus Dactylogyrus), forty-seven to the Tetraonchinae, (12 Cleidodiscus, 11 Onchocleidus, 9 Actinocleidus, 3 Haplocleidus, 3 Pterocleidus, 3 Urocleidus, 2 Tctraonchus, 1 Leptocleidus, 1 Aristocleidus, 1 Tetracleidus, and 1 Ancyrocephalus). and one to the subfamily Lepidotreminae, viz., Lepidotes collinsi Mueller, 1936. Price (1937a) lists forty-five Dactylogyrinae and nine Gyrodactylinae as foreign species (mostly European). Mueller (1936) gives six as the number of European species of freshwater Tetraonchinae. According to the above information, the species of Gyrodactylinae are about evenly distributed between North America and Europe, whereas most of the Dactylogyrinae are found in Europe and most of the Tetraonchinae in North America.