Systematic revision of the Atractidae sensu Chabaud (1978) (Nematoda; Cosmocercoidea): Maracaya belemensis n.sp. and Aplectana albae n.sp. from Amphisbaena alba in Brazil

Abstract

Two new species of Cosmocercoidea are described from the posterior intestine of Amphisbaena alba from Brazil, namely Maracaya belemensis and Aplectana albae. Maracaya belemensis n.sp. differs from the type species, Maracaya graciai, in that the spicule is more arcuate and the posterior extremity of the gubernaculum tapers more gradually. In addition, a small prevulvar swelling is present in the type species but absent in M. belemensis. Maracaya pusilla (Miranda, 1924) n.comb. differs from the new species in possessing bifid spicules and in having many more eggs in utero. Aplectana albae n.sp. most resembles Aplectana unguiculata (Rudolphi, 1819) by its short, simple spicules. It differs in that the first two pairs of postanal papillae are very close together rather than being well separated as in A. unguiculata. The disposition of caudal papillae in both new species resembles that seen in many other Cosmocercidae and genera classified in the Atractidae. On the basis of this resemblance and similarities in the form of the excretory pore, Maracaya, Shrankiana, Schrankianella, Labeonema, Ibrahimia, and Paradollfusnema are transferred from the Atractidae to the Cosmocercidae.