Nematode parasites of Orthoporus americanus (Diplopoda; Spirobolida) from Paraguay

Abstract

Three new species of the Rhigonematida (Nematoda) are described from the posterior intestine of Orthoporus americanus from Paraguay. Heth orthopori n.sp. resembles Heth hamatus Bowie, 1985 from Eumastigonus kaorinus from New Zealand in that striae posterior to the cervical collar of the females bear rows of tiny spines; it differs from this species in that all spines in the cervical collar are of approximately the same size. Rondonema nelsonae n.sp. is most similar to the type species Rondonema rondoni Artigas, 1926 from an unidentified Brazilian diplopod in that lateral spines in the cervical region of the female are conical; it differs from this species in that these spines are much smaller, and differs from all species in the genus by the shape of the tail of the male. Rhigonema carlosi n.sp. most closely resembles Rhigonema truncatum Artigas, 1926 from an unidentified Brazilian diplopod and Rhigonema subtruncatum Dollfus, 1952 from Gymnostreptus sp. from Brazil in having a short subconical tail in the female and a short blunt tail and robust arcuate spicules in the male; it differs from both species in having at least two more pairs of caudal papillae and by the shape of the distal extremity of the spicule.