Rhynchaustrobates ( Victoriabates ) uniscutatus, Smit, Harry, 2015

Smit, Harry, 2015, The water mite family Hygrobatidae Koch in Australia. The genera Aspidiobatella Cook, Australorivacarus Viets, Gondwanabates Imamura and Rhynchaustrobates Cook (Acari: Hydrachnidia), Zootaxa 4033 (4), pp. 567-583 : 582-583

Rhynchaustrobates ( Victoriabates) uniscutatus n. sp.

( Figs 12 A–E)

Type material. Holotype female, Gubarra Creek, upstream of pool, Kakadu NP, Northern Territory, Australia, 12 º 49.605 S 132 º 52.708 E, 27 -ix- 2005 ( NTM). Paratypes: one female, South Alligator River at crossing with Gunlom Road, Kakadu NP, Northern Territory, Australia, 13 º 29.704 S 132 º 28.601 E, 30 -ix- 2005 ( RMNH); one female, Kambolgie Creek, Kakadu NP, 13 º 30.169 S 132 º 23.688 E, alt. 96 m asl, 30 -ix- 2005 ( RMNH); one male, four females (QM), one male, four females, ( RMNH), Gregory River, Gregory Downs, Queensland, Australia, 18 º 38.811 S 139 º 15.008 E, alt. 68 m asl, 11 -x- 2005.

Diagnosis. Dorsum with one large plate with two pairs of glandularia, postocularia separate; venter with a large shield, incorporating the coxae but excluding the genital field in the female, incorporating the genital field in the male.

Description. Female. Idiosoma smooth, finely lineated, dorsally 397 ( 348–462) long and 344 ( 292–378) wide, ventrally 441 ( 405–510) long. Dorsum with one large plate with laterally a small extension, 324 ( 292–376) long and 267 ( 235–308) wide, with two pairs of glandularia. Postocularia not on this plate but separate. Anterior part of dorsal plate with hair-like papillae arranged in a reticulate pattern, but this pattern absent in posterior part of plate. Roof of camerostome with a short pointed process. Venter with a large shield, incorporating the coxae but excluding the genital field. First coxae fused medially. Cxgl– 4 lying close to insertions of fourth legs. Genital field 130 wide, with three pairs of acetabula. Length of P 1 –P 5: 26, 49, 35, 72, 38. Ventral margins of palp segments without projections. Length of I-leg- 4–6: 86, 96, 62. Length of IV-leg- 4–6: 104, 112, 76. Legs without swimming setae.

Male. Idiosoma dorsally 332 ( 316) long and 267 ( 275) wide, ventrally 397 ( 381) long. Dorsum as in female, dorsal plate 300 ( 275) long and 235 ( 235) wide. Venter with a ventral shield incorporating the coxae and the genital field. First coxae fused, posterior margin of fourth coxae indistinct, angular. Cxgl– 4 lying close to insertions of fourth legs. Genital field with three pairs of acetabula, gonopore 64 long. Length of P 1 –P 5: 18, 52, 30, 64, 36. Palp stockier than in female, especially P 2 and P 3. Length of I-leg- 4–6: 80, 90, 70. Length of IV-leg- 4–6: 105, 118, 80. Legs without swimming setae.

Etymology. Named for the large dorsal plate.

Remarks. The large dorsal plate is only found in R. truusae n. sp., for differences with the new species see there.