Agauopsis ripa Otto, 1999

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 : 158-160

Agauopsis ripa Otto, 1999 Figure 5 A-G

Agauopsis ripa Otto 1999: 809-811 , figs 12A-D, 13A- D.

Material examined — Paratype male, ZMH A19/00, Great Barrier Reef, Tokolakea Beach, algae and tube-worm colonies on boulders, low tide level, 15 Jun. 1997.

Short description — Length of females 369 – 440 µm, of males 349 – 460 µm. AD 1.2 times longer than wide, ds-1 level with gland pores. OC slen- der, 1.5 times longer than wide (1.2 in compressed paratype). Gland pore at 0.4, removed from cornea by the latter’s diameter. Distance from glp to cornea hardly longer than that to pc ( Figure 5A ). Pair of ds- 4 in males level with posterior corner of OC. Male PD almost as long as or slightly longer than wide. Medial costae with groups of five to six canaliculi. Plate outside costae reticulated and with fine canaliculi.

Arrangement of canaliculi on ventral plates rather uniform, reticulation faint. GA in both female and male slightly longer than wide. Anterior margin of female GA truncate, that of male GA ovate ( Otto 1999: fig. 12D), arched ( Figure 5B ) or rather truncate ( Otto 1999: p. 810). Spermatopositor large, in compressed male extending beyond anterior margin of GA ( Figure 5B ). Male with 47-50 pgs and pair of outlying setae. That pair closer to lateral margin than to outer ring of pgs.

Gnathosoma about 1.8 times longer than wide (of slightly compressed paratype). Rostrum shorter than gnathosomal base (0.8:1) ( Figure 5C ). P-2 2.9- 3.0 times longer than wide. P-4 short, about 1.5 times longer than P-3, two basal setae different in length (paratype) ( Figure 5D ). Tectum slightly arched.

Integument of lateral flank of legs pierced by canaliculi; medial flanks with few delicate pores. Lateral spine on genu I slightly smaller than medial one. Telofemur III 2.3 times longer than high. Ventral seta on telofemora III and IV in basal half, at about 0.4. Tibia II with three (rarely four) ventral setae. Tibiae III and IV with two spiniform, dentate ventral setae. Tip of tarsus II medially with spurlike pas, laterally with doubled pas, one of pas long, the other short. Fossa membranes on tarsi III and IV short and small. Claws on tarsus I ( Figure 5E ) shorter than following claws. Claws on tarsi II to IV with accessory process; pectines extending to about middle of claw shaft ( Figure 5F and G ).

Remarks — Agauopsis ripa is very similar to A. sordida Bartsch, 1992 (outlined below). According to Otto (1999), the two species differ in the length of the rostrum. According to the paratype studied there is no marked difference. Examination of more material from the type localities may prove A. ripa to be a synonym of A. sordida .

Amongst the material studied by Otto, one of the males had a GA with ovate anterior margin GA ( Otto 1999: fig. 12D). In general males of tropical Indo-West Pacific Agauopsis species have a GA with a truncate to slightly arched anterior margin.

Distribution and biology — South-western Pacific, Australia, Queensland, Great Barrier Reef ( Otto 1999). All records are from intertidal and lower tidal zones where it lived amongst algae, tube worm colonies, and sediment between mangrove roots.

Figures

FIGURE 5: Agauopsis ripa Otto, 1999, male: A – lateral margin of OC; B – genitoanal plate; C – gnathosoma, ventral; D – P-3 and P-4; E – tip of tarsus I, ventromedial; F – tip of tarsus II, ventromedial (one of lateral parambulacral setae obscured, the other in broken line); G – tip of tarsus III, ventral. (T, tectum) Scale line = 50 µm.