Austraturus carewae, Pešić & Smit, 2023

Pešić, Vladimir & Smit, Harry, 2023, A new species of the water mite genus Austraturus K. O. Viets, 1978 from Victoria, Australia (Acari: Aturidae: Notoaturinae), Memoirs of Museum Victoria 82, pp. 49-53 : 50-52

Austraturus carewae sp. nov. (figs. 1–2)

Zoobank: https://zoobank.org/urn:lsid:zoobank.org:act:F18549BB-864A-4461-936A-233948312903

Material examined. Holotype male ( NMV), McCrae Creek , Victoria, Australia, 37.81729219 S, 145.5059157 E, 14 November 2018, leg. C. Kellar and K. Stevenson (sequenced; BOLD: AFWM084-21 ).

Diagnosis. A pair of enlarged setae on the dorsal posteromedial plate placed close and laterally to the anterior pair of glandularia, posterior margin of posteromedial plate with a rounded extension; tips of Cx-I bluntly pointed; P-2 with three stout denticles; IV-L-4 ventral margin with a rounded extension in the proximal part, bearing six setae of which the anterior is long and stout.

Description. Male: idiosoma dorsally 347 long and 305 wide, ventrally 430 long. Ventral and dorsal shield with a colour pattern as illustrated in fig. 2A–B. Frontal margin rounded; dorsum with paired anteromedial plates, an unpaired posteromedial plate and two paired lateral plates. Anterolateral dorsal platelets with two pairs of glandularia, posterolateral dorsal plates with one pair of glandularia without enlarged setae. Posteromedial plate with only the anterior pair of glandularia with enlarged setae; posterior margin with a somewhat broad and rounded extension. Gnathosomal bay 101 long, tips of Cx-I bluntly pointed, coxae fused to ventral shield, suture lines lightly visible. Glandularia of Cx-IV closer to posterior margin than to anterior margin. Near anterior end of gonopore two pairs of glandularia, the anterior pair closer to each other than posterior pair. Genital field with numerous acetabula, poorly visible in ventral view. Gonopore narrow, 72 long. Palp: dorsal length/height, ratio: P-1, 20/22, 0.9; P-2, 70/64, 1.1; P-3, 55/32, 1.73; P-4, 117/21, 5.5; P-5, 31/10, 3.1; P-2/P-4 length ratio 0.6. P-2 with three stout ventral denticles, P-4 slender (fig. 1C).

Legs: dorsal length of I-L-2-5: 48, 58, 81, 81; dorsal length of IV-L-1-6: 59, 77, 72, 84, 83, 108. IV-L-4 ventral margin with a rounded extension in the proximal part, bearing six setae of which the anterior seta is longer and stouter ( Figures 1D-E ), dorsal sector concave, here with three setae; IV-L-5 ventrally with four setae.

Etymology. Named after Melissa E. Carew, University of Melbourne.

Discussion. The new species is most similar to Austraturus sagittalis Smit, 2018 . The latter species, known from a male collected in a small creek in Queensland, differs from the new species in a broad arrow-shaped posterior extension of the posteromedial plate. While the new species’ anterior pair of glandularia of the posteromedial plate are more distanced from the associated setae, the latter’s setae are comparatively more slender. Other differences can be found in the shape of IV-L-4 and -5 (IV-L-4 ventrally with eight setae and an anteroventral extension, and more medially three setae of which the most anterior seta is the longest; IV-L-5 ventrally with six setae). Moreover, in A. sagittalis the tips of Cx-I are truncated and P-2 possesses only two stout ventral denticles (see Smit 2018). Austraturus projectus Cook, 1986 , a species known from Tasmania, is somewhat similar in the shape of the posteromedial dorsal plate and its setae, but the anteromedial dorsal plates are projecting, the tips of Cx-I are truncated and P-2 has two rather stout, short ventral setae.

Figures

Figure 1. Austraturus carewae sp. nov, ♂ holotype: A, idiosoma, dorsal view; B, idiosoma, ventral view; C, palp; D, right IV-leg (inset: IV-L-4, 2x enlarged); E, left IV-L-3-6 (inset: IV-L-4, 2x enlarged). Scale bars = 100 μm.