Ribeiroia

Ribeiroia () is a genus of trematode parasites that sequentially infect freshwater snails in the family Planorbidae (ramshorn snails) as first intermediate hosts, fish and larval amphibians as second intermediate hosts, and birds and mammals as definitive hosts (see ). In North America, infection by Ribeiroia has been linked to amphibians with limb malformations. The connection between parasitic infection and limb malformations has generated questions about (a) whether parasite-induced malformations in amphibians are increasing (see ), and (b) the consequences of such abnormalities for amphibian population conservation (see ).

== Taxonomy == Ribeiroia is a genus of parasites in the class Trematoda, phylum Platyhelminthes. Currently three species and one subspecies of Ribeiroia are recognized: R. ondatrae in North America, R. marini in the Caribbean, R. m. guadeloupensis on the Caribbean island of Guadeloupe, and R. congolensis in Africa (Johnson et al. 2004). The trematode Cercaria lileta is also closely related to Ribeiroia, and molecular sequence data indicates that it may be a species of Ribeiroia (Johnson et al. 2004). All species of Ribeiroia share the distinctive morphological characteristic of esophageal diverticula (i.e., two short dead-end branches that extend laterally from the esophagus). Other genera closely related to Ribeiroia include Cladocystis trifolium, Cathemasia, and Echinostoma (Johnson et al. 2004). See Johnson et al. (2004) for more details on morphological and ecological differences as well as phylogenetic relationships between these species.