Agauopsis itassussensis, Pepato, Almir R. & Tiago, Cláudio G., 2005

Pepato, Almir R. & Tiago, Cláudio G., 2005, Two new species of Agauopsis (Halacaridae, Acari) from Southeastern Brazil, Zootaxa 994, pp. 1-12 : 2-5

Agauopsis itassussensis sp. nov.

( Fig. 1 )

Holotype: Female ( MZUSP 16630), from coarse sand at 8 m depth near Itassucê Islet, Barequeçaba Beach (23º 50' S, 45º 27' W), May 1st 2003, coll: J. Norenburg, C. Santos, G. Y. Kawauchi and L. F. Netto.

Paratypes: Four females (author's collection), from intertidal coarse shell debris and gravel on south end of Barequeçaba Beach faced to the Itassucê Islet (23º 50' S, 45º 27' W), April 30th 2003, coll.: J. Norenburg

Comparative material examined: Agauopsis okinavensis Bartsch, 1986 . Female identified by Otto (1999) mounted on a single slide [Australian National Insect Collection ( ANIC), slide nº. 866]. From Great Barrier Reef, John Brewer Reef (18°38'25" S 147°04' 42"E), collected April 11th 1998 by SCUBA diving, on coarse sand, 15 m depth.

Description. Female: Idiosoma 430–460 m long, 316–340 m wide. Anterior dorsal plate with one frontal and two lateral spines, an anterior areola and two convergent costae joined by a transversal ridge slightly anterior to insertion sites of ds­1. Such areola and costae are made up of quadrangular panels and alveolus in deeper cuticle layers while the transversal ridge between AD costae is devoid of them. AD 145–168 m long and 150– 173 m wide with ds­1 attached at 0.30–0.34 of its overall length.

Pair of ds­2 attached to membranous cuticle between AD and OC. Ocular plate 135– 142 m long and 47–56 m wide, caudate, with two conspicuous corneas. The caudiform prolongation of OC reaches half of the distance between insertion of legs III and IV. Posterior dorsal plate measures 241–251 m in length and 149–203 m in width. This plate bears two costae similar to the one found on AD. Between their posterior extremities to level of the posterior pair of gland pores these costae are parallel one to each other, posterior to gp they are divergent. Posterior dorsal plate also bears ds­3 and ds­4. Adanal setae inserted nearby posterior end of PD, on anal papillae.

Epimeral plates separated by stripes of membranous cuticle, with papillate areola in their margins. Anterior epimeral plate posteriorly extended with three pairs of setae. It measures 221–245 m in length and 311–339 m in width. Posterior epimeral plates with one dorsal and three ventral setae.

Genitoanal plate 123–128 m long and 155–169 m wide. It has a pair of areolae lateral to GO, which almost reaches the first pair of pgs level. Distance between anterior edge of GA and GO 58– 63 m. Genital opening measures 68–75 m in length and 33–40 m in width.

Gnathosoma dorsally ornamented by tiny granules. It measures 161–168 m in length and 69–76 m in width with the rostrum equaling 0.54–0.56 of its overall length. Palp longer than rostrum and with a dorsal seta on P2; one slender and tapering spine on P3; two terminal hair­like setae and two spurs on P4.

Ornamentation on leg cuticle made up of tiny granule arranged in a large mesh pattern. Leg chaetotaxy with the spines setae referred with Roman numerals: leg I, 1,2,8(V),5(II),8(III),5(I); leg II, 1,2,5,4,5,3; leg III, 1,2,3,3,4,3; leg IV, 1,2,3,3,4,3. When observed under 1,600 times magnification most setae on proximal segments of legs proved to be haired with very thin filaments. Spines on leg I with denticles apically but without the lateral rows, which are observed in other species. Tarsus I with one pair of parambulacral setae, one pair of ventral setae, one solenidion and one famulus posteriorly inserted. Tarsus II with a pair of parambulacral setae. Tarsi III and IV without any parambulacral setae. All tarsi with smooth lateral claws and median claw present only at tarsus I.

Etymology: Agauopsis itassussensis is named after the type locality, near the Itassucê Islet.

Remarks: Agauopsis itassussensis sp. nov. belongs to the okinavensis group which comprises three species: A. okinavensis Bartsch, 1986 recorded from Okinawa ( Japan), Great Barrier Reef and Coral Sea; A capillosa Otto, 1999 recorded from the Great Barrier Reef; and an undescribed species represented by a juvenile collected from Bermudas Islands ( Bartsch, 1986, 1999, Otto, 1999). Agauopsis itassussensis can be readily separated from A. capillosa Otto, 1999 by the posteriorly extended AE. In other hand, such feature is shared with the very similar species A. okinavensis which, however, lacks a caudiform extension on OC, which ends slightly beyond insertion of leg III. Furthermore, A. okinavensis displays the posterior costae of PD uniformly divergent instead of running close to each other along their posterior portion.

Figures

FIGURE 1: Agauopsis itassussensis sp. nov., female: A­ Idiosoma dorsal view. B­ Idiosoma ventral view. C­ Posterior dorsal plate near insertion of ds­ 4. D­ Leg I, ventral view. E­ Leg II, lateral view. F­ Leg III, lateral view. G­ Leg IV, lateral view. H­ Tarsus I, posterior view. I­ Gnathosoma, lateral view. J­ Gnathosoma, ventral view. Scale bars: A, B, D – G, I, J: 50 m; C, H: 25 m.