Morphological and molecular characterisation of one new and one known species of Makatinus Heyns, 1965 (Dorylaimida: Aporcelaimidae) from Ukraine, with new insights into its phylogeny

Abstract

Summary Makatinus ukrainicus sp. n. and a population of M. aquaticus, both from Ukraine, are described and illustrated using morphological, morphometric and molecular (28S rDNA) data. The new species is characterised by its 2.17-2.70 mm long body, 20-23 μm broad lip region, odontostyle 20.5-25 μm long at its ventral side and 23-27 μm long at its dorsal side, 591-672 μm long neck, uterus simple and 163-174 μm long or 2.0-4.7 corresponding body diam. long, V = 49.5-52.8, tail convex-conoid (29-39 μm, c = 61-86, c′ = 0.6-0.9), spicules 86-93 μm long, two pairs of adcloacal supplements, and 17-21 closely and regularly spaced ventromedian supplements without an hiatus. In general, the Ukrainian population of M. aquaticus fits well those previously known from Spain and Hungary, and its study confirms the identity of this species. The morphological and molecular data of the Ukrainian populations reveal an interesting diversity within the genus, which might not be a monophyletic taxon.