Arrenurus (Arrenurus) hyalinus, Smit, Harry, 2010

Smit, Harry, 2010, Australian Arrenurus (Acari, Hydrachnidia) with the description of eleven new species, Zootaxa 2541, pp. 1-26 : 3-5

Arrenurus (Arrenurus) hyalinus n. sp.

( Figs. 2A–D )

Material examined. Holotype male, The Deep Creek downstream of falls, Deep Creek Conservation Park, South Australia, Australia, 35° 38.582 S 138° 13.868 E, 5 April 2008 ( SAM). Paratypes: 1 male, 1 female ( ZMAN), 1 female ( SAM), Stubbs Waterhole, Arkaroola, South Australia, Australia, 30° 18’ S 139° 24’ E, 25 October 2001.

Diagnosis. Male: Petiole asymmetrical with two hyaline spoon-shaped extensions. Female with very short genital plates and fourth coxal plates almost without medial margin.

Description. Male: Idiosoma brownish, 729 (802) long and 470 (547) wide, anterior margin slightly concave. Dorsum posteriorly with a ridge, medially with a blunt pointed extension ( Fig. 2A ). Pygal lobes short, medially with a short hyaline extension. Gonopore 40 long. Genital plates about 2 ½ times as long as wide ( Fig. 2B ), total width of genital field 283. Petiole asymmetrical, with two spoon-shaped hyaline extensions of different size. Petiole inserted ventrally near excretory pore. Setae associated with petiole bifurcated. Lengths of PI-PV: 34, 74, 50, 76, 34; PII medially with two setae ( Fig. 2C ). Lengths of I-leg-4-6: 114, 122, 104. Lengths of IV-leg-4-6: 104, 206, 154. IV-leg-4 with a very long spur, 138 long. Third leg with relatively few swimming setae, fourth leg with numerous swimming setae.

Female: Idiosoma brownish, 976 (932) long and 761 (745) wide, slightly truncated posteriorly. Dorsal shield complete, 810 (770) long and 607 (575) wide. Anterior idiosoma margin rounded. First coxal plates not extending to anterior idiosoma margin. Fourth coxal plates almost without medial margin. Gonopore 130 long. Genital valves with a small strip of sclerotization along medial margin ( Fig. 2D ). Genital plates very short, width of genital field 292. Lengths of PI-PV: 42, 82, 54, 84, 36; palp as in male. Lengths of I-leg-4-6: 120, 136, 110. Lengths of IV-leg-4-6: 186, 194, 130.

Etymology. Named after the several hyaline extensions.

Remarks. The petiole of the male is unique and will distinghuish it easily from other members of the genus.

Figures

FIGURE 2 A – D. Arrenurus hyalinus n. sp., (A – C holotype male, D paratype female): A = dorsal view; B = ventral view; C = palp; D = dorsal view. Scale bars A, B, D = 200 µm, C = 50 µm.