Unionicola (Downesatax) curvipalpis, 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 : 5-8

Unionicola (Downesatax) curvipalpis n. sp.

( Figs. 1–4 )

Material examined. Holotype female, Home Billabong, Kakadu NP, Northern Territory, Australia, 22 July 1994 ( NTM). Paratypes, 2 females (NT, ZMAN), same data as holotype; 1 female, outlet Upper Pool, Edith Falls, Katherine Gorge NP, Northern Territory, Australia, 30 July 1994 ( NTM); 1 female, Lawn Hill Creek at campground, Lawn Hill NP, Queensland, Australia, 18° 42.011 S 138° 29.235 E, 10 October 2005 (QM); 1 male (QM), 2 females (QM, ZMAN), Hann Crossing (stagnant), Lakefield NP, Queensland, Australia, 14° 45’57.30” S 144° 04’57.30” E, 4 September 2000.

Diagnosis. Palp long and bowed, especially PIV; setal tubercles of PIV absent.

Description. Female: Idiosoma soft, 405 (316–486) long and 348 (243–413) wide. Posterior apodemes of anterior coxal plates extending just beyond posterior margin of third coxal plates. Length of third + fourth coxal plates 144. Posterior margin of fourth coxal plates with a short projection. All coxal plates with a reticulate pattern. A pair of glandularia in the secondary sclerotisation of the posteriomedial corner of fourth coxal plates. Genital field with two pairs of genital plates. Each anterior plate with two acetabula, extending medially in a short flap-like extension with two enlarged setae. Each posterior genital plate with three acetabula, and one enlarged seta. Lengths of PI-PV: 14, 128, 54, 128, 70. Palp long and bowed, especially PIV. Setal tubercles of PIV absent; ventrodistal peg-like seta of PIV small, not on a tubercle. Lengths of I-leg-4-6: 176, 194, 116. First leg with reduced number of setae on ventral margin, only one long distal seta present, without papillae. Lengths of IV-leg-4-6: 206, 255, 215. Claws of legs with clawlet, without claw blade.

Male: Idiosoma 259 long and 211 wide. Length of third + fourth coxal plates 112. Posterior apodemes of anterior coxal plates extending well beyond anterior margin of third coxal plates. Posterior margin of fourth coxal plates without projections. All coxal plates with a reticulate pattern. A pair of glandularia in the posteriomedial corner of fourth coxal plates (or in the secondary sclerotisation, this cannot be discerned); associated seta of these glandularia long. Genital field terminal, with 5 pairs of acetabula, the two anterior pairs distanced from the three posterior pairs; all acetabula arranged one behind the other. Genital field not fused anteriorly. Genital field flanked by a pair of glandularia on a small tubercle. Length of PI-PV: 10, 86, 33, 84, 56. PIV without setal tubercles (most of the small setae lost), ventrodistally with a small peg-like seta. Lengths of Ileg-4-6: 146, 160, 98; I-leg-6 somewhat bowed, fluted setae absent. Lengths of IV-leg-4-6: 160, 170, 128; IVleg-5 with two short swimming setae. Claws of legs with clawlet, without claw blade.

Etymology. Named for its curved palp.

Remarks. The new species is close to U. vidrinei , but differs in the longer and more bowed palp, while the first leg segments are longer.

Figures

FIGURE 1 – 4. Unionicola curvipalpis n. sp. 1 – 3, holotype female, 1, ventral view; 2, palp; 3, I-leg- 5 - 6; 4, paratype male, ventral view. Scale bars = 50 µm.