New species of Xyalidae (Nematoda : Monhysterida) from Australian ocean beaches

Abstract

Eight new species of Xyalidae are described from Australian ocean beaches. Gonionchus australis, sp. nov., has non-capitate spicules with recurved tips and lacks longitudinal crests on the cuticle. G. alastairi, sp. nov., has cuticular crests and a strong dorso-caudal gubernacular apophysis. Xyala brevibucca, sp. nov., has a very shallow buccal cavity and small amphids. X. hanleyi, sp. nov., is similar but has fewer longitudinal crests, a longer thinner tail and weakly curved spicules. X. macramphis, sp. nov., has sexually dimorphic amphids, larger in males, and many somatic setae. Omicronema australis, sp. nov., has a very deep buccal cavity and males have two rows of ventral post-anal setae. O. australis from southern Australia are larger than those from the north. O. coronalata, sp. nov., has distinctive cephalic annulation, and O. nana, sp. nov., is very small, weakly annulated and with large amphids. Separation of the genus Omicronema from Xyala is supported.