The Asian Fish Tapeworm Bothriocephalus acheilognathi: a Potential Threat to Native Freshwater Fish Species in Mexico

Introduction of the parasite Bothriocephalus acheilognathi Yamaguti, 1934 with the herbivorous carp Ctenopharyngodon idellus, and other cyprinids, has been documented in almost every continent, except Antarctica. This study presents the current geographical distribution of this cestode in the freshwater fish of Mexico, highlighting infections in autochthonous and endemic species. It compiles existing information and presents original data. B. acheilognathi is widely dispersed among the freshwater fish of Mexico, being recorded to date in 49 fish species from 26 genera, 7 families and 5 orders. B. acheilognathi is reported from Mexico for the first time in Dionda ipni, Notropis celayensis, Yuriria alta, Gambusia vittata, Poecilia butleri, P. mexicana, Poeciliopsis baenschi, Poeciliopsis sp., Cichlasoma cyanoguttatum and C. labridens. The new hosts identified in this study bring the total number of known host species to 102 in 14 families and 7 orders of freshwater fishes around the world. Given its wide distribution among Mexican freshwater fish species, the abundance of the parasite and its high pathogenicity, parasitological data for B. acheilognathi should be considered as an important factor in native fish conservation policies. Biological changes in the freshwater habitats in Mexico caused by the introduction of exotic fish species and their parasites are virtually ubiquitous and extremely difficult to eradicate once established. As such, they should be considered as one of the most serious threats to native fish conservation.