Arrenurus (Megaluracarus) niveensis, Smit, Harry, 2010

Smit, Harry, 2010, Australian Arrenurus (Acari, Hydrachnidia) with the description of eleven new species, Zootaxa 2541, pp. 1-26 : 10-11

Arrenurus (Megaluracarus) niveensis n. sp.

( Figs. 6A–E )

Type material. Holotype male, Nive River at crossing with road A10, Tasmania, Australia, 42° 10.006 S 144° 54.801 E, alt. 588 m, 22 March 2008 ( TMAG). Paratypes: 1 male, 1 female ( TMAG), 1 male ( ZMAN), same data as holotype.

Diagnosis. Idiosoma length of male> 1400; male with a posteriorly widened cauda, posteriorly with a short, obliquely located seta; genital field of male short and rounded; palp with two different types of setae, dorsally stout and grooved and ventrally thin and not grooved.

Description. Male: Idiosoma brownish to reddish-brown, 1442 (1315–1437) long and 737 (672–729) wide. D1 and D4 on small humps. Dorsum anteriorly with a half-circular area without body pores ( Fig. 6A ). Cauda long, widened posteriorly, posterior margin slightly undulating, dorsally with an obliquely located seta, which extends beyond posterior margin. In lateral view posterior margin of cauda slightly concave ( Fig. 6C ).

Coxal field not extending to anterior idiosoma margin. Gonopore 80 long, genital plates short and rounded, not extending to lateral idiosoma margin ( Fig. 6B ). Width of genital field 324. Lengths of PI-PV: 46, 98, 66, 118, 52. PII with a large patch of setae, these setae in the dorsal half of the patch stout and grooved (and setae hardly visible individually), in the ventral half thinner and not grooved ( Fig. 6D ). PIII with a long medially located seta. PIV with a large antagonistic seta, anterodorsal margin with three setae. Lengths of I-leg-4-6: 211, 227, 186. Lengths of IV-leg-4-6: 251, 235, 192. IV-leg-4 without spur, but with a short, blunt anteroventral extension.

Female: Idiosoma reddish-brown, broad egg-shaped, 1407 long and 1186 wide. Dorsal shield complete, 1146 long and 1025 wide. Idiosoma without posterolateral corners. Dorsum anteriorly with a half-circular area without body pores. Coxal field not extending to anterior idiosoma margin. Medial distance of fourth coxal plates larger than width of one genital valve. Gonopore 186 long and 194 wide, with a medial chitinized strip. Genital plates short and broad, slightly bowed ( Fig. 6E ); width of genital field 640. Lengths of PI-PV: 42, 110, 70, 120, 54. Palp as in male, but PIV anterodorsally with four setae. Lengths of I-leg-4-6: 186, 202, 150. Lengths of IV-leg-4-6: 243, 300, 227.

Etymology. Named after the type locality.

Remarks. The male of the new species is characterized by the posteriorly widened cauda, in combination with the obliquely located posterior seta. Both male and female have a characteristic palp, with a large patch of differently shaped setae. The male is most close to A. maria Smit , but differs in the lack of the small posterior hyaline extensions, while the seta near the posterior margin of the cauda of the new species is obliquely located, larger and extending beyond the posteriuor cauda margin.

Figures

FIGURE 6 A – E. Arrenurus niveensis n. sp., (A – D holotype male, E paratype female): A = dorsal view; B = ventral view; C = lateral view cauda; D = palp; E = ventral view. Scale bars A – C, E = 200 µm; D = 50 µm.