Agauopsis arabia Bartsch and Chatterjee, 2001

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 : 149-150

Agauopsis arabia Bartsch and Chatterjee, 2001 Figure 1 A-E

Agauopsis arabia Bartsch and Chatterjee 2001: 322- 326 , fig. 1-12.

Additional material examined — Two females, Bay of Bengal, Andaman Islands (by T. Chatterjee forwarded to the author for identification; cf. Chatterjee et al., 2004).

Short description — Length of female 450 – 490 µm, of male 416 µm (according to Chatterjee et al., 2004, female 450 – 500 µm, male 410 – 450 µm). Dorsal plates with costae. Surface of costae not reticulated but canaliculi arranged in groups. Integument between costae with epicuticular droplets forming a reticulum; canaliculi within reticulum (polygons) more delicate than within costae. AD slightly more than 1.2 times longer than wide. Transverse costa on AD at about 0.5 and more narrow than longitudinal costae, middle part slightly curved posteriad ( Figure 1A ). Pair of ds-1 level with gland pores. OC 1.4 times longer than wide; glp on OC removed from posterior cornea, situated about halfway between that cornea and pc ( Figure 1B ) or at 0.4 along lateral margin of OC. PD of female and male almost equal-shaped, 1.2-1.3 times longer than wide. Medial costae on PD rather narrow, width in middle part of plate equalling three groups with canaliculi, else costae two groups wide. Pair of ds-4 level with or immediately posterior to edge of OC; pair of ds- 5 in anterior half of PD, outside costae, pair of ds-6 on PD.

Ventral plates faintly reticulated, with rather evenly spread canaliculi within each polygon, mostly with (6-)11-17(-18) canaliculi per polygon. Anterior margin of female GA truncate, that of male slightly convex. Male with 36-39 pgs around GO and pair of outlying setae. That pair of setae about halfway between ring of pgs and lateral margin of GA. Interval between anterior margin of each GA and GO equalling about length of GO. Spermatopositor large, 0.7 of length of GA and extending to anterior margin of that plate.

Length of gnathosoma 2.1-2.2 times its width. Rostrum somewhat longer (1.1-1.2 times) than gnathosomal base. P-2 2.7-2.9 times longer than high ( Figure 1D ). P-4 twice as long as P-3, its two basal setae almost equal in length. Tectum with scaliform lamella ( Figure 1C ).

Tibia II ventrally with one bipectinate and two dentate, spiniform setae. Tibiae III and IV with two dentate, spiniform setae. Telofemora III and IV 2.0-2.2 times longer than high. Ventral seta on telofemora III and IV in apical half. Tarsi III and IV with short lateral fossa membranes. Claws II to IV each with minute accessory process and pectines with delicate tines ( Figure 1E ).

Remarks — The rostrum of Agauopsis arabia is slightly longer than the gnathosomal base whereas in most of the species mentioned from the tropical Indo-West Pacific the rostrum is shorter than the base, exceptions are A. longirostris Bartsch, 2015 and A. moorea Bartsch, 1992 . The rostrum of A. longirostris is distinctly longer (1.7-1.8 times) than the basis, that of A. moorea 1.0-1.1 times longer. Differences between A. arabia and A. moorea are in the position of the gland pore on the OC, in the anterior ( A. arabia ) and posterior half ( A. moorea ); furthermore, males of A. moorea have a small spermatopositor which does not extend to the anterior margin of the GA.

Distribution and Biology — Arabian Sea (Goa, Kerala), Bay of Bengal (Andrah Pradesh, Andaman Islands) ( Bartsch and Chatterjee 2001; Chatterjee et al. 2004; Chatterjee and Guru 2011). Most records are from tidal algae.

Figures

FIGURE 1: Agauopsis arabia Bartsch and Chatterjee, 2001: A – idiosoma, dorsal, female; B – lateral margin of OC, male; C – gnathosomal base, dorsal, female; D – gnathosoma, lateral, female; E – tip of tarsus IV, ventral, female. (glp, gland pore; pa, porose areola; pc, pore canaliculus; T, tectum) Scale line = 50 µm.