Molecular and morphological characterisation of Sphaerolaimus haurakiensis n. sp. (Nematoda, Sphaerolaimidae) from the New Zealand continental shelf

Abstract

ABSTRACTA new species of the predatory nematode genus Sphaerolaimus is described from the continental shelf off northeastern New Zealand, and an updated list of valid Sphaerolaimus species is provided. Sphaerolaimus haurakiensis n. sp. is characterised by eight longitudinal rows of 10–16 μm long somatic setae becoming gradually sparser posteriorly, six outer labial papillae and four 6–7 μm long cephalic setae in a single circle, amphideal fovea located at level of posterior buccal cavity, arcuate spicules 1.1 cloacal body diameters long, gubernaculum with curved apophyses almost parallel to the spicules, and vulva located at 55% of body length from anterior. S. haurakiensis n. sp. is the only valid species of this common, globally distributed genus recorded to date from the New Zealand Economic Zone, but several other species are likely to be present. Preliminary phylogenetic analyses based on sequences of the small subunit (SSU) 18S rDNA gene indicate that the new species is closely related to S. uncinatus Freudenhammer, 1970 a species found on continental margins of the Mediterranean and Northeast Atlantic.