Halacarus higginsi Newell, 1984

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 : 30

Halacarus higginsi Newell, 1984

Halacarus higginsi: Newell (1984: 54–56, figs 103–107) .

Diagnosis. Length of female 588–633 µm, of male 476–537 µm. Frontal spine short, triangular, its length 0.3 and 0.1 times that of AD and idiosoma, respectively. Posterior part of AD rather wide, linguiform, posterior margin truncate. Pair of glp-1 at 0.6 relative to length of AD. Pair of ds-1 anterior to glp-1. Ocular plates slender, feebly demarcated, each with minute, pycnotic cornea; canaliculus in posterior angle. Pairs of ds-5 and ds-6 level with glp-4 and glp-5, respectively, setae separated from pores by slightly more than glp diameter. Female GA very short, anterior margin straight. Pair of pgs-1 removed from margin of GA by 9.0 times distance between margins of GA and GO. Male with 24–39 pgs on either side of GO. Pair of pgs- 1 in striated integument anterior to GO.

Gnathosoma about 1.8 times longer than wide. Rostrum longer than gnathosomal base, extending just beyond level of end of P-2. Basal seta on P-2 at 0.6. Seta on P-3 spiniform, with rounded tip. Integument of legs punctate. Telofemur, genu and tibia I with 2, 2, 4 spiniform ventral setae. Basalmost ventral spine on telofemur I in basal half. Trochanters I to IV with 1, 1, 2, 1 setae, basifemora I to IV with 2, 3, 2, 2 setae. Tibiae I to III each with four bristle-like ventral setae; on tibia II distal one of ventromedial setae bipectinate. Tarsi I to IV with 2, 2–4, 2–4, 2–4 ventral setae, respectively. Tarsi III and IV with three to four and three dorsal setae. Paired claws of all tarsi with small accessory process bearing three to five minute tines.

Remarks. The species can be identified on the basis of the short, triangular frontal spine, the position of the ds- 1 anterior to the glp-1 and the accessory processes on the paired claws with three to five minute teeth. Females have an unusual short GA with a straight anterior margin.

Distribution and ecology. Juan Fernandez Islands. Amongst coralline algae.