Arrenurus (Arrenurus) okavango, Smit, 2012

Smit, H., 2012, New records of the water mite family Arrenuridae from the Afrotropical region, with the description of 11 new species and two new subspecies (Acari: Hydrachnidia), Zootaxa 3187, pp. 1-31 : 7-10

Arrenurus (Arrenurus) okavango n. sp.

( Figs. 19–22)

Material examined. Holotype male, ditch along Okavango swamp at Drotsky’s Camp, south of Shakawe, Botswana, 18° 25’ 24,2” S 21° 53’ 28,17” E, 23-vii-1996 ( RMNH) . Paratype: male, inlet of Okavango River near Drotsky’s Camp, south of Shakawe, Botswana, 23-vii-1996 ( RMNH) .

Diagnosis. Dorsal shield of male with a raised idiosoma, petiole short and convex, hyaline membrane with a concave posterior margin.

Description. Male: Idiosoma brownish, 1013 (1004) long, 575 (563) wide and 810 (810) high. Idiosoma anteriorly narrowed, anterior margin straight but pointed in paratype. Cauda short, pygal lobes absent. Dorsal shield incomplete, posteriorly narrowed and dorsal shield raised; only D2 and D3 lying on the dorsal shield. In lateral view the raised dorsal shield has two lobes. A number of lateral glandularia on humps. Anterior coxae extending beyond anterior idiosoma margin. Posterior margin of fourth coxae indistinct. Gonopore 56 long. Genital field long, extending to lateral idiosoma margin and widened laterally. Cxgl2 and cxgl4 on small humps. Petiole simple with its basis slightly broader, posterior margin convex. Hyaline membrane with a concave posterior margin. Lengths of PI-PV: 30, 76, 58, 80, 50. PIV stocky, with a slightly concave dorsal margin. PII medially with two anteroventral setae and more dorsally another seta. Lengths of I-leg-4-6: 124, 120, 166; dorsal margin of I-leg-6 with numerous long, fine setae. Lengths of IV-leg-4-6: 227, 174, 162; IV-leg-4 without spur.

Female: Unknown.

Etymology. Named for its occurrence in the Okavango swamp.

Remarks. The new species belongs to a group of Afrotropical species with a raised dorsal shield, i.e. Arrenurus chappuisi , A. grandis , A. altissimus and A. coronopetiolatus n. sp. The new species is most close to A. chappuisi (in parentheses), but differs in a two-lobed raised dorsal shield (without lobes), the petiole is broad and short (more elongate) and in lateral view the petiole is directed straight (upturned).