Unionicola (Giselatax) trisetica, Smit, Harry, 2008

Smit, Harry, 2008, Australian Unionicola (Acari: Hydrachnidia: Unionicolidae), with the description of two new subgenera and eight new species, Zootaxa 1674, pp. 1-26 : 15

Unionicola (Giselatax) trisetica n. sp.

( Figs. 19–22 )

Material examined. Holotype male, pool Valentine Springs, W of Kununurra, Western Australia, Australia, 18 September 1998 ( WAM). Paratypes: 2 females, same data as holotype ( WAM); 1 male, 5 females, Spillway Creek, near Lake Argyle, Western Australia, 20 September 1998 ( ZMAN); 1 male, pool Lennard River, Windjana Gorge NP, Western Australia, Australia, 9 September 1998 ( ZMAN).

Diagnosis. IV-leg-4 with two long, curved heavy setae and one straight, heavy seta.

Description. Male: Body soft, idiosoma 494 (454–510) long and 356 (332–373) wide. Apodemes of anterior coxal plates extending well beyond anterior margin of third coxal plates. A pair of glandularia incorporated into sclerotisation of posteromedial corners of fourth coxal plates. Length of Cx3+4 259. Fourth coxal plates with small posterior projections. Genital field terminal with five pairs of acetabula, the two anterior pairs somewhat distanced from the three posterior pairs. Genital field located terminal, genital plates not fused ventrally in holotype, but fused in paratype. Lengths of PI-PV: 10, 112, 30, 86, 66. PIV with one long and one very short setal tubercle, peg-bearing tubercle shorter than longest tubercle. Lengths of I-leg-4-6: 219, 190, 170. First leg with long, heavy setae, with small papillae. Lengths of IV-leg-4-6: 87, 413, 324. IV-leg-4 with one heavy, sword-like seta and two heavy, curved setae. All legs with numerous fine, long setae. Claws with clawlet, without claw blade.

Female: Body soft, idiosoma 891 (834) long and 664 (640) wide. Apodemes of anterior coxal plates extending well beyond anterior margin of third coxal plates. A pair of glandularia incorporated into sclerotisation of posteromedial corners of fourth coxal plates. Fourth coxal plates with short posterior projections. Genital field terminal with four genital plates and five pairs of acetabula, each anterior plate with two acetabula, each posterior plate with three acetabula. Anterior genital plates each with two enlarged setae, posterior genital plate with one enlarged seta. Lengths of PI-PV: 12, 164, 42, 142, 98; palp as in male. Lengths of I-leg-4-6: 340, 247, 223. Lengths of IV-leg-4-6: 292, 429, 365. Fluted setae of first legs with papillae. IV-leg-5 with two stiff swimming setae, IV-leg-4 with three swimming setae. Third leg without difference between leg setae and swimming setae. Legs with clawlet, without claw blade.

Etymology. Named for the three heavy setae of IV-leg-4.

Remarks. The new species is close to U. lundbladi K.O. Viets , which has the male IV-leg-4 with one straight and one curved heavy setae, the latter more pointed than in the new species. IV-leg-4 of the new species has two curved heavy setae. Furthermore, U. lundbladi has IV-leg-4 with one long, narrow heavy seta, in the new species this seta is broader and shorter. The curved terminal seta of IV-leg-5 of U. lundbladi is absent in the new species. Females cannot be separated from other females of the subgenus or from females belonging to other subgenera, e.g. U. longiseta .

Figures

FIGURE 19 – 22. Unionicola trisetica n. sp. 19 – 21, holotype male, 19, ventral view; 20, palp; 21, IV-leg- 3 - 5; Scale bars = 50 µm; 22, paratype female, ventral view. Scale bar = 200 µm.