Anphira xinguensis sp. nov. (Isopoda, Cymothoidae) a gill chamber parasite of an Amazonian serrasalmid fish, Ossobius xinguense JÉGU, 1992

Abstract

Anphira xinguensis sp. nov. (Isopoda, Cymothoidae) is described from the gill chambers of a recently discovered "pacu", Ossubtus xinguense JÉGU, 1992 (Senasalmidae). The parasites and their hosts were collected on the Xingu River in Pará State, Brazil. Anphira THATCHER, 1993, is redefined and characterized as having: a cephalon immersed in the first pereonite and rotated downward; flattened, plate-like coxae on all 7 pereonites; rounded "foot-shaped" mandibles without incisors; pleonites produced laterally; elongate uropods and simple lamellar pleopods with with a well developed appendix masculinum on pleopod 2 of both sexes. The new species differs from the type, Anphira branchialis THATCHER, 1993, in having: females that are usually asymmetrical; mouths directed ventrally or posteriorly; antennae of 7 articles and uropods with rami one and a half to two times the length of the bases