Redescription of Echinocoleus hidrochoeri (Travassos, 1916) (Nematoda: Trichuridae) from Hydrochoeris hydrochaeris Linnaeus, 1766 (Rodentia: Caviidae) from Argentina

ROBLES, R; EBERHARDT, MAT; BAIN, O; BELDOMENICO PM

JOURNAL OF PARASITOLOGY

AMER SOC PARASITOLOGISTS

Lugar: Washington, Estados Unidos; Año: 2013 vol. 99 p. 624 - 633

0022-3395

Twenty eight Capillariinae species were recorded in rodents; one of these was described from a caviomorph rodent, Hydrochoeris hydrochaeris L. 1766, and placed in genus Echinocoleus by Moravec (1982). However, both original description and subsequent contributions of Echinocoleus hydrochoeri are poor and incomplete. Specimens of this species were recovered during a parasitological survey of capybaras from two localities from Corrientes Province, Argentina. In this paper, E. hydrochoeri is redescribed, reviewing its belonging to the genus Echinocoleus. Moreover, a new geographical distribution is reported. The redescription of the E. hydrochoeri is based on morphologic and morphometrical features, such as intestine ending in cloaca beside ejaculatory duct, caudal bursa composed of 2 large ventrolateral lobes, with an fleshy internal part fleshy and an membranous external part membranous (they are not united dorsally with a membrane), terminal part of cylindrical cirrus ornamented with thin and thick spines (and particular pattern distribution), sclerotized spicule sclerotized, one pair of papillae in male, and vulvar appendage in female, and 3 bacillary bands (1 ventral and 2 lateral). The morphological comparison among Echinocoleus species showed that E. hidrochoeri and E. cyanopicae (type species from birds) are the most different within the genus, and that E. hidrochoeri and E. auritae (both mammal parasites), seem be the most similar. However, the paucity of distinctive morphological characteristics from capillariids results in poor descriptions. Consequently, the difficult taxonomic and nomenclatural situations of the capillariid group suggest that E. hidrochoeri may be changed of genus when more species are redescribed including more characters. In this paper, the generic and specific analyses were performed in order to establish new standards for futures studies on the systematic position of Capillariinae species. This survey presents new relevant morphological information and a new record of a capillariid species from Argentina, being the fourth for this country.