Abstract
The Amphilinidea represents a peculiar and little‐known order of monozoic cestodes. In a study on Crenicichla cincta collected from the Gama River in the Brazilian State of Amazonas, some amphilinideans were found in the small intestine of the fish. The morphological and genetic characterization of these parasites revealed that they represent a new genus and species, which was named Pochelia juruaensis gen. et sp. n . The new genus differs from the other six currently assigned to the Amphilinidea by the combination of the following features: the vagina does not cross the ejaculatory duct, the terminal limb of the uterus is lateral and tubular, the seminal receptacle is subglobular, slightly narrower than and anterior to the ovary, the ovary is subglobular, and there is a terminal, weakly developed and median depression. The 18S and 28S rDNA sequences of 1533 and 1358 bp, respectively, differed markedly from those of other amphilinideans. Phylogenetic reconstructions confirmed the assignment of P . juruaensis gen. et sp. n . in the Amphilinidea as well as its proximity to Amphilina and Schizochoerus , and the relationships were better supported by 18S rDNA sequences. This is the first report of an enteric amphilin. The order Amphilinidea is most likely monophyletic and occupies a basal position among the cestodes together with Gyrocotylidea. An updated key for the genera of the Amphilinidea is also presented.