Description of Rotylenchus nexus n.sp. (nematoda, hoplolaiminae) from Brazil, with some observations on the nematode genus Calvatylus

Abstract

Rotylenchus nexus n.sp. was found in woodland soil in Brazil. Females are 0.60–0.72 mm long and have a conoid-truncate head without any visible annulation; spear 28–31 μm, the conus being about half the spear length; basal knobs of spear convex posteriorly and slightly concave anteriorly; outlet of dorsal oesophageal gland 4.3–7.2 μm behind spear knobs; tail dorsally convex-conoid with 7–12 annules ventrally and phasmids at anus level or up to four annules behind it. Males are 0.55–0.69 mm long, head higher and narrower than that of females, with four or five usually very faint annules; spear 21–25 μm; tail about twice as long as body width at cloaca level, conoid, tip usually mucronated.