Halacarus multispinus Bartsch, 1981

Bartsch, Ilse, 2011, Halacarus socius (Acari: Halacaridae), description of the male and diagnoses of species of the Halacarus actenos group, Zootaxa 2800, pp. 18-40 : 32-33

Halacarus multispinus Bartsch, 1981

Halacarus multispinus: Bartsch (1981a: 37–39, figs 1–9) .

Diagnosis. Length of female 967 µm. Frontal spine long and slender, its length almost half that of AD and 0.2 times that of idiosoma. Posterior part of AD linguiform. Pair of glp-1 at 0.7. Pair of ds-1 level with pair of glp-1. Corneae and ocular plates absent. Canaliculi within striated integument. Pair of ds-5 slightly anterior to level of glp-4, ds-6 level of glp-5; setae removed from gland pores. Female GA rounded. Anterior pair of pgs level with posterior end of PE. Distance between pgs-1 and anterior margin of GA equalling 1.6 times that between anterior margins of GA and GO. Ovipositor extending beyond GO to anterior margin of GA.

Gnathosoma slender. Rostrum distinctly longer than gnathosomal base, extending to end of P-2. Basal seta on P-2 at about 0.7. Spine on P-3 slender and pointed. Legs longer than idiosoma. Trochanters I to III with 1, 1, 1(?) setae, basifemora I to III with 2, 3, 2 setae. Telofemur, genu and tibia I with 5, 2, 4 spiniform ventral setae. Basalmost ventral spine on telofemur I at 0.2. Ventromedial seta on genu II smooth. Tibia II with two bristle-like ventromedial and ventrolateral setae; distalmost of ventromedial setae delicately bipectinate. Tarsi I to IV with 2, 1, 1, 1 ventral setae, tarsi III and IV with four and three dorsal setae. Paired claws of all tarsi slender, without pecten.

Remarks. Legs I and II bear an unusual large number of setae, none of the other Halacarus species has five spiniform ventral setae on telofemur I.

Distribution and ecology. Indian Ocean, northeast of the island Mayotte, at 300–350 m depth.