Hexaxonopsis clavigera ( Walter, 1922 )

Smit, Harry, 2017, New species of aturid water mites from southern Africa (Acari: Hydrachnidia: Aturidae), Zootaxa 4273 (2), pp. 287-295 : 289-291

Hexaxonopsis clavigera ( Walter, 1922)

( Fig 2 A–D)

Material examined. Type material. Axonopsis claviger , holotype male, Weisser Nil bei Kosti, Plankton , Sudan, 24-ii-1921, leg. Chappuis (slide O/27 NMB). Other material : Namibia. Male, Cubango River at Rundu , 17° 54.570 S 19° 45.685 E, 24-vii-1996 ; one male, Zambezi River, Katima Mulilo , 17° 29.160 S 24° 17.055 E, 20-vii-1996 ; one male, Okavango River at Popa Falls , 18° 0 6.992 S 21° 35.062 E, 21-vii-1996 .

Description. Male: Idiosoma dorsally 395 long and 332 wide, ventrally 405 long. Dorsal shield 300 wide, with five pairs of glandularia and one pair of setae without glands. Dorsal shield fused anteriorly with ventral shield, with three spine-like projections posteriorly to the eyes. Excretory pore fused to dorsal shield. Anterior margin of idiosoma straight. First and second coxae each with a lateral and a medial hook-like projection. A pair of glandularia are located between the genital field and the insertions of the forth legs. Genital field with three pairs of acetabula. Gonopore 38 long, posterior acetabulum 34 long. Length of P1–5: 32, 46, 30, 68, 28. Length of I-leg-4- 6: 54, 74, 74. Length of IV-leg-4–6: 82, 102, 92 (till tip of segment). IV-Leg-5 expanded distally with 15–20 short setae; IV-leg-6 with two rows of dorsomedial setae. Swimming setae: III-leg-4 two, III-leg-5 four, IV-leg-4 with two and IV-leg-5 with three.

Remarks. The slide of the holotype is in very poor condition. The genital field is clearly visible, details of the fourth leg are not clearly visible and the coxae are squashed. Apart from one broken hook-like projection of one of the first coxae, no other hook-like projections are visible anymore. Given the similarity of the fourth leg of the holotype and the specimens reported here, I assigned the specimens from southern Africa to Walter’s species. Walter (1922) didn’t illustrate the medial hook-like projections, but I assume that he overlooked these as they are not clearly visible in ventral view.

Figures

FIGURE 2. Hexaxonopsis clavigera (Walter), male. A = dorsum; B = venter; C = palp; D = IV-leg- 4 – 6. Scale bar = 50 µm.