Description of Panagrolaimus hamomucronatus sp. n. (Rhabditida, Panagrolaimidae) from Spain

Summary A new species of the genus Panagrolaimus , P. hamomucronatus sp. n., is described from oak bark with lichens in the southern Iberian Peninsula. This species is characterised by having body 1.15-1.18 mm long in females and 0.91-1.16 mm long in males, habitus slightly sigmoid after fixation in females and ‘J’-shaped in males, cuticle with transverse striations, lateral fields with three longitudinal incisures, a lip region with six conoid lips ending in a setiform process, amphids rounded to oval, stoma with cheilostom bearing scarcely refringent rhabdia, a gymnostom as long as wide with very refringent rhabdia and stegostom short with well-sclerotised rhabdia, pharynx with pharyngeal corpus subcylindrical (1.6-1.9 times isthmus length) with metacorpus not swollen, nerve ring surrounding the anterior part of the isthmus, excretory pore at isthmus level, deirids at level of the isthmus, female reproductive system monodelphic-prodelphic with ovary without flexures and post-vulval uterine sac 0.6-0.7 times the corresponding body diam. long, rectum 1.3-1.5 times anal body width long, female tail conoid with fishhook-like mucron and phasmids at 73-76% of its length, male reproductive system monorchid with testis ventrally flexioned anteriorly, eight pairs of genital papillae (three precloacal and five postcloacal) with phasmids located posterior to the papilla GP6, spicules with manubrium ventrally bent and lamina with reduced dorsal hump and well-developed ventral velum, and gubernaculum slightly deltoid. Its phylogenetic position is studied based on 18S rDNA. An updated list of species is provided together with a new illustrated key to species identification.