Aturus neooligoporus, Tuzovskij, 2023

Tuzovskij, Petr V., 2023, A new water mite species of the genus Aturus Kramer, 1875 (Acari, Hydrachnidia, Aturidae) from Kazakhstan, Zootaxa 5254 (1), pp. 142-146 : 142-143

Aturus neooligoporus sp. n.

Figs 1–6

Type material. Holotype: female, slide 9957, Asia , Kazakhstan, Turkestan Province , Tyulkubaskiy District , Aksu-Zhabagly Nature Reserve, Aksu stream, 42°19′36.4″N 70°22′17.8″E, 1350 m, depth about 1 m, substrates large stones, mosses, white sand, 15.08.2019, leg. V. Stolbov.

Diagnosis. Idiosoma frontal margin with small median incision, dorsal shield with secondary sclerotization laterally and posteriorly, excretory pore located in zone of secondary sclerotization, first three pairs of slit organs fused with glandularia Vi, Hi and Sci, respectively, i4 and i5 free, contours coxal plates IV slightly developed, setae Pe and Le situated between posterior margin of coxal shield and genital plates, genital field with five pairs of acetabula and two of fine medial setae on each side.

Description. Female: Idiosoma broad (L/ W 1.15), with convex lateral margins, frontal margin with small median incision ( Fig. 1 ). All idiosomal setae simple. Dorsal shield very large, covering nearly the whole dorsum, posterior margin concave, bearing trichobothria Oi and 3 pairs of glandularia (Hi, Li, Si), with slightly developed secondary sclerotization along lateral margin and posteriorly; glandularia Hi far from Li and Si, separation ratio L Hi-Li / Li-Si 2.7. First pair of slit organs (i1) fused with sclerites bearing glandularia and setae Vi, i2 fused with Oe, i3 fused with Sci, i4 free, located on soft integument behind to Le. Excretory pore posterior to zone of primary sclerotization.

Coxal shield ( Fig. 2 ) large, covering about 4/5 of the ventral side, with small posteromedian indentation. Setae Pe and Le situated between posterior margin of coxal shield and genital plates in zone of the secondary sclerotization; Se located in latero-caudal position between coxal shield and acetabular plate on each side. Contours of coxal plates IV weakly developed. Near posterior margin of venter a row of 5 pairs of circular or oval subequal acetabula. Each genital plate with two medial fine short setae. Fifth pairs of slit organs and setae Pi located caudally in the soft integument.

Pedipalp: P-1 short, with single dorsodistal seta; P-2 relatively large, with convex ventral margin, bearing four dorsal setae and a short pointed ventrodistal spine, P-3 with straight or slightly concave ventral margin and two dorsodistal setae; P-4 relatively long, with slightly convex ventral margin, two unequal ventral setae (thick and thin) distally to middle of segment, short distal peg-like seta and one or two fine dorsodistal setae ( Fig. 3 ).

I–IV-Leg-1–5 armed mainly thick setae ( Figs. 4–5 ). Leg claws with three clawlets, central clawlet longer than other ones, lamella moderately developed with slightly convex ventral margin ( Fig. 6 ).

Measurements (n=1). Idiosoma L 450, W 390; dorsal plates L 345, W 280; distance between setae Hi/Li and Li/Si 114 and 42, respectively; capitulum L 95, W 60–65; pedipalp segments (P-1-5) L/W: 24/18, 60/48, 36/36, 80/30, 36/12; genital acetabula D or L 18–24; leg segments L: I-Leg-1–6: 40, 40, 40, 60, 65, 71; II-Leg-1–6: 48, 40, 42, 58, 70, 80; III-Leg-1–6: 47, 48, 53, 78, 95, 95; IV-Leg-1–6: 60, 65, 72, 102, 108, 90.

Male. Unknown.

Etymology. The species is named neooligoporus as it has many characters in common with the Asian species A. oligoporus .

Habitat. Running waters.

Distribution. Asia, Kazakhstan: Turkestan Province.

Remarks. The new species is similar to Asian species Aturus oligoporus Tuzovskij, 1994 and European A. brachypus K. Viets, 1936 in the structure of the idiosoma and genital field. Differences between the females of A. neooligoporus sp.n. and A.oligoporus in the following characters (character states of A. oligoporus are given in parentheses, data from Tuzovskij 1994): Setae Le and Pe situated in the secondary sclerotization between posterior margin of coxal shield and genital plates, Fig. 2 (setae Le and Pe are fused to posterior margin of coxal shield, Fig. 8 ); P-2 with ventrodistal spine, Fig. 3 (without ventrodistal spine, Fig. 9 ); glandularia Le and fourth pair of slit organs distinctly separated, Fig. 1 (fused to each other, Fig. 7 ). The female A. brachypus differs from A. neooligoporus sp.n. in the following characters: Idiosoma frontal margin without median incision; idiosoma and pedipalps is small dimensions: idiosoma L/W 390/350 μm, pedipalp total length 185 μm; separation ratio Dgl-3-4/4-5 ca. 3.0 ( Gerecke et al. 2016).

Figures

FIGURES 1–2. Aturus neooligoporus sp.n., female: 1, dorsal view; 2, ventral view. Scale bar: 1–2 = 100 μm.

FIGURES 3–6. Aturus neooligoporus sp.n., female: 3, pedipalp, lateral view; 4, II-Leg-4–6; 5, IV-Leg-4–6; 6, claw of leg IV. Scale bars: 3, 5–6, 4 = 50 μm.

FIGURES 7–9. Aturus oligoporus Tuzovskij, 1994, female: 7, dorsal view; 8, ventral view; 9, pedipalp, modified after Tuzovskij (1994).