Atractides (Atractides) bellus, Pešić & Smit, 2021

Pešić, Vladimir & Smit, Harry, 2021, Water mites of the genus Atractides Koch, 1837 from Kyrgyzstan (Acari: Hydrachnidia: Hygrobatidae) with the description of six new species, Acarologia 61 (2), pp. 332-355 : 333-337

Atractides (Atractides) bellus n. sp.

Zoobank: 796A37C3-40DB-4E14-983D-04CFCF4CA899

Figures 1-3

Type material — Kyrgyzstan: Holotype ♂, dissected and slide mounted ( RMNH), KR14 Karakal region , road to May Saz pass, spring, 42°25.033 ′ N, 79°02.657 ′ E, 3348 m a.s.l., 12

Aug. 2013, leg. Pešić & Smit. Paratypes: 1♀, same site and data as the holotype, leg. Pešić &

Smit, dissected and slide mounted ( RMNH).

Diagnosis — Integument striated; Cx-I+II plate caudally protruding forming a large and irregular, mace-like mediocaudal extension; acetabula in an obtuse triangle; excretory pore smooth; Vgl-1 not fused to Vgl-2; P-3 with one seta on medial surface; male P-2 ventral margin without a projection, P-3 with a small, lamellar extension in the centre.

Description — General features — Integument striated, muscle insertions unsclerotized. Cx-I+II plate caudally protruding, mediocaudal margin forming a large and irregular subcuticular extension, apodemes of Cx-II directed laterally ( Figures 1A , 3A ). Acetabula in an obtuse triangle. Excretory pore smooth; Vgl-1 not fused to Vgl-2. Palp with sexual dimorphism, P-2 ventral margin straight or slightly convex, without projection, P-3 with one seta on medial surface, P-4 sword seta nearer to distoventral seta. I-L-5: S-1 longish and blunt, S-2 bluntly pointed and thicker than S-1; I-L-6 curved, proximally thickened, from the centre to the claw furrow with subparallel dorsal and ventral margins ( Figures 2C , 3D ). Male — Mediocaudal margin of Cx-I+II extending beyond the posterior margin of Cx-IV; genital plate anterior margin nearly straight, with a narrow border of secondary sclerotization, posterior margin slightly indented ( Figure 1A ); P-3 with a small ventral extension in distal half, P-4 ventral setae very long ( Figures 2 A-B). Female — Mediocaudal margin of Cx-I+II not extending beyond the posterior margin of Cx-IV; mediocaudal margin of Cx-IV with an indentation ( Figure 3A ); Ac-2 smaller than Ac-1 and -3; P-2-4 ventral margin nearly straight, P-4 slenderer than in male, ventral setae short ( Figure 3C ).

Measurements — Male — Idiosoma L 731, W 547; maximum diameter Dgl-4, 22. Coxal shield L 378; Cx-III W 434; Cx-I+II mL 256, Cx-I+II lL 406. Genital field L/W 151/180, ratio

0.84, L Ac-1-3: 42-50, 45-51, 51-53. Ejaculatory complex ( Figure 1B ) L 136.

Gnathosoma — Palp total L 397; dL/H, dL/H ratio: P-1, 41/27, 1.49; P-2, 87/59, 1.46; P-3,

95/52, 1.85; P-4, 135/42, 3.2; P-5, 39/15, 2.6; length ratio P-2/P-4 0.64. Gnathosoma L 167,

chelicera total L 244.

Legs — I-L-5 dL 232, vL 178, dL/vL ratio 1.3, maximum H 66, dL/maximum H 3.5, S-1 L 114, L/W ratio 9.1, S-2 L 98, L/W ratio 7.0, distance S-1-2, 16, dL ratio S-1/2 1.16; I-L-6 dL

152, central H 27, dL/central H ratio 5.7; L I-L-5/6 ratio 1.53.

Female — Idiosoma L 925, W 738; maximum diameter Dgl-4, 23. Coxal shield L 378;

Cx-III W 508; Cx-I+II mL 194, Cx-I+II lL 366. Genital field L/W 213/231, genital plates L

134, gonopore L 191, pregenital sclerite W 128, maximum diameter Ac-1-3: 56, 53, 58; egg maximum diameter (n=1) 215.

Gnathosoma — Palp total L 417; dL/H, dL/H ratio: P-1, 39/31, 1.25; P-2, 94/56, 1.69; P-3, 106/46, 2.3; P-4, 136/34, 3.95; P-5, 42/16, 2.7; length ratio P-2/P-4 0.69. Chelicera total L 250.

Legs — I-L-5 dL 267, vL 205, dL/vL ratio 1.31, maximum H 72, dL/maximum H 3.7, S-1

L 127, L/W ratio 9.6, S-2 L 108, L/W ratio 7.0, distance S-1-2, 16, dL ratio S-1/2 1.18; I-L-6

dL 175, central H 27, dL/central H ratio 6.58; L I-L-5/6 ratio 1.53.

Etymology — Named for being a beautiful species.

Discussion — The combination of a characteristically shaped Cx-I+II plate (caudally protruding forming a large and irregular, a mace-like mediocaudal extension) and palp (P-3 with one seta on medial surface, in male P-3 with a small, ventral extension in distal half) is unique and separates the new species from all other members of the genus.

Distribution — Kyrgyzstan ; so far only known from one spring (see Fig 18B in Pešić and Smit 2020) in Tien Shan mountains at an elevation of about 3,300 meters.

Figures

Figure 1 Atractides bellusn. sp., ♂ holotype, KR14 May Saz, Kyrgyzstan. A, idiosoma, ventral view. B, photograph of ejaculatory complex. Scale bar = 100 µm.

Figure 2 Atractides bellusn. sp., ♂ holotype, KR14 May Saz, Kyrgyzstan. A – palp, medial view; B – palp, lateral view; C – I-L-5 and -6. Scale bars = 100 µm.

Figure 3 Atractides bellusn. sp., ♀ paratype, KR14 May Saz, Kyrgyzstan. A – coxal field, partial view; B – genital field; C – palp, lateral view; D – I-L-5 and -6. Scale bar = 100 µm.