Description of Penjatinema novaezeelandiae sp. n. (Rhabditida: Cephalobidae) from New Zealand – a second species of a rare genus

Abstract

A new species of

Penjatinema, P. novaezeelandiae sp. n., is described from coastal sand dune habitats in New Zealand. The new species resembles the type species, P. natalense Heyns & Swart, 1998, described from similar habitats in South Africa. It differs from P. natalense in the following characters: longer body (672-859 vs 590-720 μm), longer tail (69-88 μm vs 40-50 μm; c = 9.7-10.4 vs c = 11.9-17.5; c’ = 4.2-4.8 vs c’ = 2.2-2.8), a more anterior position of excretory pore (20-23 vs 34-40 annuli from anterior end), phasmids located anterior to anus in females, longer (39-44 μm vs 34-36 μm) and more slender spicules in males, arrangement and number of cuticular ridges (eight + four vs ten), presence of four prominent highly refractive rings located in-between the anteriormost annuli, and absence of deirids in both sexes (vs presence in males). The phylogenetic relationships of the new species are inferred from molecular data. Maximum likelihood analyses of the 5 end (including D1/D2/D3 domains) regions of 28S rDNA sequences support a position of Penjatinema nested among Cephalobidae.