Halacarus griseus Bartsch, 1987

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 : 29-30

Halacarus griseus Bartsch, 1987

Halacarus griseus: Bartsch (1987: 75–79, figs 1–13) .

Diagnosis. Length of female 914–1025 µm, of male 790–884 µm. Epicuticula on plates and legs delicately reticulate or with fingerprint-like to punctate ornamentation. Frontal spine long, its length equalling 0.4 times that of AD and 0.1–0.2 times that of idiosoma. Gland pores on lateral protrudings, at 0.6–0.7 relative to length of AD. Pair of ds-1 immediately anterior to glp-1. Part of AD posterior to glp-1 spiniform in outline. Cornea small, round; canaliculus in striated integument. Pairs of ds-5 and ds-6 immediately adjacent to glp-4 and glp-5, respectively. Female GA rounded. Pair of pgs-1 at level of posterior part of PE. Distance from pair of pgs-1 to margin of female GA about 0.9 times that between anterior margins of GA and GO. Anterior margin of GA almost halfway between pgs- 1 and GO. Anterior margin of male GA rounded. Pair of pgs-1 level with posterior seta on PE, anterior margin of GA extending just beyond level of edge of PE. GO in middle of GA, surrounded by about 90 pgs.

Gnathosoma about 2.4 times longer than wide. Rostrum extending beyond P-3, its length almost twice that of gnathosomal base. Basal seta of P-2 at 0.8. Telofemur, genu and tibia I with 2, 2, 4 tapering ventral setae. Basalmost ventral seta on telofemur I at 0.6. Trochanters I to IV with 1, 1, 2, 1 setae, basifemora I to IV with 2, 4, 2, 2 setae. Ventromedial setae on genu II and tibia II bipectinate. Tarsi I to IV with 2, 2, 4–5, 4 ventral setae; tarsi III and IV with four and three dorsal setae. Paired claws with small accessory process but no pecten.

Remarks. This is a large species with long frontal spine and rostrum, slender palps and slender legs. Differences to the long-spined and long-legged H. leptopus Bartsch, 2002 and H. longiunguis Police, 1909 are listed below.

Distribution and ecology. Mediterranean, from sublittoral sediment (11–20 m depth).