Arrenurus (Megaluracarus) pseudomargatellus, Smit, Harry, 2010

Smit, Harry, 2010, Australian Arrenurus (Acari, Hydrachnidia) with the description of eleven new species, Zootaxa 2541, pp. 1-26 : 11-14

Arrenurus (Megaluracarus) pseudomargatellus n. sp.

( Figs. 7A–G )

Material examined. Holotype male, Buaraba Creek, Ravensbourne NP, Queensland, Australia, 27° 22 S 152° 15 E, 4 November 2005 (QM). Paratypes: 1/1/1 (QM), 0/1/0 ( ZMAN), same data as holotype; 1/0/0, Bundaroo Creek, Conondale NP, Queensland, Australia, 26° 41.653 S 152° 36.767 E, 3 November 2005 ( ZMAN); 1 male (AMS), 1 male ( ZMAN), Tonoum Brook, Royal NP, New South Wales, 8 November 2001.

Diagnosis. Posterior part of male cauda triangular with straight lateral margins; female with short genital plates, gonopore with a pair of sclerotized strips.

Description. Male: Idiosoma yellowish-reddish brown, legs red, anteriorly rounded, 1110 (1093–1183) long and 632 (583–640) wide. Dorsal shield incomplete, 470 (437–494) wide. Cauda relatively short, not distinctly set off in lateral view ( Fig. 7C ), posterior part of cauda triangular, with straight lateral margins ( Fig. 7A ). Posterior stout seta of obliquely located. The two paratypes from Royal NP with a longer triangular part of the cauda ( Fig. 7G ). Close to posterior cauda margin an obliquely located stout seta and a small, irregularly shaped hyaline membrane (the structure close to the forementioned seta). Anterior coxae not extending to anterior idiosoma margin. Gonopore 68 long, genital plates short, anterior margin straight and laterally rounded ( Fig. 7B ); width of genital field 243. Lengths of PI-PV: 32, 72, 42, 82, 34. PII with a large patch of medial setae, extending over the entire anterior margin of segment; part of PII with patch of setae extending far anteriorly ( Fig. 7D ). Lengths of I-leg-4-6: 130, 140, 142; I-leg-6 with numerous long, thin setae ( Fig. 7E ). Lengths of IV-leg-4-6: 170, 132, 194; IV-leg-4 with a short, blunt spur. Second, third and fourth legs with numerous swimming setae.

Female: Idiosoma yellowish brown, legs red, anteriorly rounded, posterolateral corners of idiosoma absent. Idiosoma 1004 (936) long and 834 (786) wide. Dorsal shield complete, 689 (632) long and 628 (583) wide. First coxae not extending to anterior idiosoma margin. Medial margin of fourth coxal plates larger than medial margin of third coxal plates. Medial distance of third+ fourth coxal plates about the width of one genital valve. Medial corner of fourth coxal plates indistinct. Gonopore 174 long and 140 wide, central area with a strip of sclerotization, medially of this sclerotized area a pair of sclerotized strips (fig. 7F). Lengths of PI-PV: 38, 78, 46, 82, 40; palp as in male. Length of I-leg-4-6: 122, 140, 124. Length of IV-leg-4-6: 170, 156, 154. Second, third and fourth legs with numerous swimming setae.

Deutonymph: Idiosoma 575 long and 470 wide, integument papillate. Provisional genital plates with 13– 14 acetabula. Width of third + fourth coxal plates large, almost the width of provisional genital field. PII with a small patch of setae. Second, third and fourth legs with swimming setae, but less than in adult.

Etymology. Named for its resemblance with A. margatellus Cook.

Remarks. The new species is close to A. margatellus Cook from Tasmania. The latter species is larger (1307–1535), has the posterolateral margins of the cauda concave and the stout seta of the cauda symmetrical.

Figures

FIGURE 7 A – G. Arrenurus pseudomargatellus n. sp., (A – E holotype male, F paratype female, G paratype male): A = dorsal view; B = ventral view; C = lateral view; D = palp; E = I-leg- 5 - 6; F = ventral view; G = ventral view. Scale bars A – C, F – G = 200 µm; D – E = 50 µm.