Molecular assessment of the host specificity of <i>Promonobothrium</i> tapeworms (Cestoda: Caryophyllidea), parasites of suckers (Catostomidae) in North America: from strict specialists to generalists

An expanded dataset of caryophyllidean tapeworms (Cestoda) of the genus Promonobothrium Mackiewicz, 1968, parasites of suckers (Cypriniformes: Catostomidae) in North America, was used to reassess the host specificity of these parasites. Molecular data from newly collected specimens from diverse hosts revealed contrasting patterns in host range among congeneric tapeworms, ranging from strict specialists (half of all species, namely P. minytremi, P. fossae, P. mackiewiczi, P. papiliovarium and Promonobothrium sp. from Ictiobus niger) parasitizing a single host species, to family generalists (three species, namely P. hunteri, P. ingens and P. rogersi) occurring in fishes of different sucker subfamilies (Catostominae and Ictiobinae). Promonobothrium currani is considered a congeneric specialist and P. ulmeri a subfamily generalist. The high proportion of generalists (40%) is exceptional in the Caryophyllidea. Based on this study, it is recommended to verify records of tapeworms from atypical hosts, preferably using molecular data from vouchered specimens (hologenophores or paragenophores). https://zoobank.org/urn:lsid:zoobank.org:pub:EBFB81F5-6565-45D4-A9B8-48C146591248