Morphological-molecular characterization and phylogenetic relationships of a new Trichuris species (Nematoda: Trichuridae) parasitic on Hydrochoerus hydrochaeris (Caviidaeae: Hydrochoerinae) from Corrientes province (Argentina

CALLEJON, R; ROBLES, M. R.; EBERHARDT M. A. T.; MONJE L; BELDOMENICO, P.; CUTILLAS, C

Congreso; XX Congreso de la Sociedad Española de Parasitología. XV Meeting del European Veterinary Parasitology College; 2017

Up to the date, 27 species of Trichuris of 11 families of North American and South American rodents have been described. Only 1 Trichuris species in each one of the families Caviidae, Dasyproctidae, Echimyidae, Geomyidae, Muridae, Myocastoridae and Octodontidae have been registered; while 2 havebeen described in Sciuridae, 4 in Heteromyidae and Ctenomyidae, and 10 in Cricetidae. This genus presents few morphological diagnostic characters, being difficult the determination at specific level. Recent studies demonstrate that the genetic marker (ITS2, cox1, cob) support the delimitation of the species. The capybara (Hydrochoerus hydrochaeris) is the living rodent of major size of the world, and he presents distribution in the American continent. The species of Trichuris registered in this host is of doubtful identification, or attributed to Trichuris myocastoris. In this study, a new species of Trichuris of H. hydrochaeris from Corrientes province is described based on morphologic and molecular characters. Also, it is compared with the species T. myocastoris described on the coypu (Myocastor coypus). The morphologic studies showed significant differences with 27 known species of Trichuris from Americanrodents, including to T. myocastoris (e.g. proportions between spicule, anterior and posterior cloacal tube, and length of the body). Also, the molecular analyses based on nuclear markers (ITS1 and ITS2), showed specimens of Trichuris of the capybara separated from other Trichuris species. It is interesting tonotice that the species T. myocastoris appeared as a sister group of Trichuris n. sp. from H. hydochaeris and both species are separated of Trichuris carleri, Trichuris mastomysi, Trichuris arvicolae and Trichuris muris with robust support. In this study, is recorded a new Trichuris species, being the ninth present species in rodents of the Argentina, and the second one registered for Caviidae.