Origins of the Monogenea of selected major taxa of Nearctic freshwater fishes

Abstract

Comment on the origin(s) of a group of parasites requires an awareness of the paleogeology of the region and historical records – phylogenies of both hosts and their parasites. The paleogeology of the Nearctic Region is described briefly and 11 families of Nearctic freshwater fishes for which phylogenetic information is available are considered: Acipenseridae, Polyodontidae, Catostomidae, Ictaluridae, Fundulidae, Poeciliidae, Cyprinodontidae, Percidae, Centrarchidae, Moronidae, and Percopsidae. A previous hypothesis that the Nearctic ancyrocephalids are of mixed origins is supported and the phenomena of vicariance, dispersal, host-switching, and co-evolution are demonstrated.