Agauopsis longirostris Bartsch 2015

Bartsch, I., 2015, The Agauopsis brevipalpus group (Acari: Halacaridae), descriptions of tropical Indo-West Pacific species, a key to all species, their geographical distribution and reflections on dispersal routes, Acarologia 55 (2), pp. 147-169 : 155

Agauopsis longirostris Bartsch 2015 : figs 7A-M, 8A-J.

Short description — Length of female 510 µm, of male 450 – 460 µm. Dorsal plates with costae. Costae with groups of three to six canaliculi, these porose groups hardly delimited and costae without reticulate ornamentation. Remainder of plate reticulated, each polygon including about five to eight delicate canaliculi. AD 1.2 times longer than wide. Pair of ds-1 level with gland pores; transverse bar of H-shaped costa on AD at 0.5. Each OC with oblique costa; gland pore immediately posterior to cornea, at 0.4. PD with pairs of longitudinal medial and marginal costae. Medial costae in anterior half three to four porose groups wide. Female and male PD 1.1 and 1.3 times longer than AD, respectively. Female PD 1.1 times longer than wide, male PD prolonged, 1.2 times longer than wide. PD with pair of ds- 5 in lateral margin of medial porose costae, at 0.4 relative to length of PD.

Polygons of ventral plates with 9-15 canaliculi; canaliculi in centre as well as along periphery of each polygon. Anterior margin of female and male GA truncate. Male GA with 36-38 perigenital setae arranged in two rings around GO and a pair of outlying setae distinctly separated from outer ring of pgs.

Gnathosoma elongate, 2.1-2.3 times longer than wide. Rostrum 1.7-1.8 times longer than gnathosomal base. Tectum with scaliform lamella. Palps elongate. P-2 4.1-4.2 times longer than high. Length of P-4 more than twice that of P-3. Two setae in about middle of P-4 almost equal-sized.

Telofemora III and IV 2.1-2.2 times longer than high. Tibiae II to IV with 3, 2, 2 spiniform setae, either pectinate or dentate. Claws II to IV with numerous delicate tines along medial flank.

Remarks — Agauopsis longirostris is characterized by its slender rostrum and palps, the P-2 are 4.1-4.2 times longer than high, in the other species known from the Indo-West Pacific the length of the P-2 is less than 3.5 times the height (width).

Distribution and biology — Singapore. The present records are from algal turf from sheltered areas (mangroves) as well as moderately exposed sites ( Bartsch 2015).