A new species of Phyllodistomum Braun, 1899 (Digenea: Gorgoderidae) in a Neotropical catfish, with discussion of the generic relationships of the Gorgoderidae

Abstract

A new species of Phyllodistomum is described. Collected from the doradid catfish Trachycorystes insignis in western Colombia, Phyllodistomum mayesi sp. n. resembles P. spatula, P. spatulaeforme, and P. symmetrorchis by having postovarian vitellaria but differs by possessing an acetabulum significantly smaller than the oral sucker. The phylogenetic relationships of 14 genera of gorgoderids are analyzed using a suite of 19 homologous series derived from comparative morphology. The resulting phylogenetic tree has a consistency index of 77%, comparable to those found in studies at the familial and subfamilial level among digeneans. The genus Phyllodistomum has no autapomorphies and thus no support as a natural group. A classification of the Gorgoderidae is proposed. A key to the 14 genera is provided.