Morphology of Labronemella major n. sp. (Nematoda: Dorylaimida), a soil-dwelling nematode from China, including a revised key to species of the genus.

Abstract

One new species from Qinghai Province, China, Labronemella major n. sp., is described. The new species is characterized by a body length of 3.03-3.34mm; lip region wide, offset by a distinct depression, disc-like with six separated inner liplets; amphid fovea funnel-shaped, distinctly bulged on body surface in scanning electron micrographs; odontostyle long (35-39μm) with distinct lumen, aperture about 39-47% of its length; odontophore rod-like and long; guiding ring double; pharyngeal basal expansion about half of the total neck length; uterus relatively long and tripartite; vulva transverse and sclerotized; spicules 81-90μm long; ventromedial supplements 19-23; tail short, rounded to conoid. It can be differentiated from all other species of the genus by its relatively longer body, odontostyle and spicules, and wider lip region. Due to the lip region being offset by a deep constriction, and the long (three or more times the body diameter at mid-body) tripartite uterus, the new species is close to Labronemella czernowitzensis (Micoletzky, 1922) Andrássy, 2002 and Labronemella labiata Andrássy, 1985. An improved key to the genus including the new species is provided.