Descriptions of three new Longidorus species from Alaska (Nematoda: Longidoridae)

Three new Longidorus species, L. alaskaensis n. sp,, L. paralaskaensis n, sp., and L. bernardi n. sp., are described from specimens collected near Fairbanks, Alaska. Longidorus alaskaensis differs from all species of Longidorus by the presence of a caecum-like structure situated at the reflex of the oviduct. Longidorus paralaskaensis most closely resembles L. alaskaensis n. sp., L. crassus Thorne, L. picenus Roca, Lamberti & Agostinelli, and L. silvae Roca, differing from the last three of these species by having a parallel vs. a tapered lip region, and from all four by having a more narrowly rounded tail tip. Longidorus paralaskaensis differs from L. alaskaensis by having a longer odontostyle (119-128 vs. 110-118 mu m) and by lacking the caecum-like structure found at the reflex of the oviduct. Longidorus bernardi n. sp. most closely resembles L. mirus Khan, Chawla & Seshadri, from which it differs by having a longer tail with a more acutely rounded rip, a longer body length (3.5-4.6 vs. 3.0-3.6 mu m), and a larger c' value (1.6-1.8 vs. 1.3-1.6). Longidorus bernardi differs from L. sylphus Thorne, L. africanus Merny, L, auratus Jacobs & Heyns, and L, conicaudatus Khan by having a slightly expanded lip region vs. a lip region with parallel body walls and a more finely rounded tail tip.