Looking at the diversity of clinostomids (Platyhelminthes: Digenea), parasites associated with fish and water birds in Mexico and Central America by molecular and biological information

Abstract

Members of the genus Clinostomum are a group of parasites that in the adult stage reside in the oral cavity of fish-eating birds, while the larval stage known as metacercaria, are found encysted (yellow group) in muscle, oral cavity, eyes, gills, subcutaneous tissue, gonads, liver and other organs, in wild and farmed fish distributed worldwide. In the current research, we compiled information available in the GenBank database from Clinostomum spp., from different biogeographic regions in the Americas, Europe, Asia and Africa, with a special emphasis on the biodiversity of Mexico and Middle America. The genetic database was built with 394 sequences, of which 269 were obtained from 51 localities in the Nearctic and Neotropical region of Mexico, including two countries from Middle-America: Honduras and Costa Rica. Phylogenetic analyses inferred with the maximum likelihood and Bayesian inference methods, recognized 8 independent clades, corresponding to 6 species previously described in Mexico, Honduras and Costa Rica, like: C. tataxumui, C. heluans, C. cichlidorum, C. arquus, C. caffarae and C. marginatum, plus two candidate species of Clinostomum spp. (Lineage 1 and Lineage 3). The 6 species of Clinostomum distributed across Mexico are associated with five species of fish-eating birds from Ardeidae, whereas metacercariae show a host specificity pattern with fishes from families: Catostomidae, Cyprinidae, Goodeidae, Cichlidae, Eleotridae, Pimelodidae, Characidae, Profundulidae, and Poeciliidae. The ecological association between the parasites and the second intermediate hosts (fishes) have played a principal role on the distribution of Clinostomum in Mexico and Middle America.