Atractides (Atractides) tienshanensis, 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 : 344-347

Atractides (Atractides) tienshanensis n. sp.

Zoobank: 498450FF-44C3-40FC-8D33-E3D5CA3E77E1

Figures 9-10

Type material — Kyrgyzstan: Holotype ♂, dissected and slide mounted ( RMNH), KR22 Karakal region , stream, 42°44.342 ′ N, 78°53.681 ′ E, 1917 m a.s.l., 13 Aug. 2013, leg. Pešić

& Smit. Paratypes: 2♂, KR3 Ala Archa NP, rheocrenic spring, 42°36.202 ′ N, 74°28.837 ′ E,

1899 m a.s.l., 9 Aug. 2013, leg. Pešić & Smit, 2♂, dissected and slide mounted ( RMNH).

Females found together with male of A. tienshanensis n. sp. and suspect to represent the female sex of the latter specie s but not included in the type series — Kyrgyzstan: 1♀, KR22 Karakal region, stream, 42°44.342 ′ N, 78°53.681 ′ E, 1917 m a.s.l., 13 Aug. 2013, leg. Pešić

& Smit, dissected and slide mounted ( RMNH); 2♀, KR3 Ala Archa NP, rheocrenic spring, 42°36.202 ′ N, 74°28.837 ′ E, 1899 m a.s.l., 9 Aug. 2013, leg. Pešić & Smit, 1♀ dissected and slide mounted ( RMNH).

Diagnosis — Integument striated; glandularia maximum diameter ˂ 30 µm; excretory pore smooth; Vgl-1 not fused to Vgl-2. Male: genital field with acetabula in an obtuse triangle, genital plate L/W ratio 0.9-1.0, anteriorly irregularly covex, genital setae in a dense row flanking the gonopore but in scattered arrangement at the lateral and posterior margins; P-2 ventrodistal margin convexly protruding, here with a rugose surface; P-4 ventral setae not exceeding tip of P-5, sword seta nearer to distoventral seta; I-L-5 dL/H ˃ 3.0, setae S-1 and S-2 more heteromorphic, S-1 longish, S-2 thicker, proximally enlarged, S-1-2 separation short, ˂

20 µm; I-L-6 stouter, dL/H ratio 4.4-4.7.

Description — General features — Integument striated, muscle insertions unsclerotized; mediocaudal margin Cx-I nearly truncate, apodemes of Cx-II in an acute angle with the median line ( Figure 9A ). Excretory pore smooth; Vgl-1 not fused to Vgl-2. Palp with sexual dimorphism, P-4 sword seta nearer to distoventral seta. I-L-5 setae S-1 and S-2 distally narrowed, bluntly pointed, S-1 longish, S-2 thicker, proximally enlarged, distance S-1-2 short; I-L-6 stout, slightly curved, proximally thickened ( Figure 9D ). Male — Genital field with acetabula in an obtuse triangle, anterior margin of secondary sclerotization irregularly convex, posterior margin of primary sclerotization slightly indented ( Figure 9A , 10A ); P-2 ventral margin distally convex, not forming a ventrodistal projection, with an irregularly rugose surface, P-3 stout, ventral margin slightly concave, P-4 slightly protruding near proximoventral seta ( Figures 9 B-C). Female — Acetabula in a weakly curved line ( Figure 10E ); P-2 without projections, ventrodistal margin rounded, P-3/4 straight ( Figures 10 F-G).

Measurements. Male (holotype ; in parentheses specimen from KR3) — Idiosoma L 584 (666), W 431 (498); maximum diameter Dgl-4, 23 (26). Coxal shield L 319 (372); Cx-III W

353 (406); Cx-I+II mL 122 (136), Cx-I+II lL 238 (269). Genital field L/W 120 (123)/123 (142),

ratio 0.97 (0.87), L Ac-1-3: 45-48 (48-52), 44-47 (41-48), 38-40 (42). Ejaculatory complex L

(143).

Gnathosoma — Palp total L 273 (326); dL/H, dL/H ratio: P-1, 30/28, 1.07 (38/33, 1.14);

P-2, 63/50, 1.25 (74/69, 1.1); P-3, 61/38, 1.59 (75/50, 1.5); P-4, 86/34, 2.5 (103/47, 2.2); P-5,

33/14, 2.4 (36/16, 2.3); length ratio P-2/P-4 0.73 (0.72). Gnathosoma vL 131 (152); chelicera total L 209 (253).

Legs — I-L-5 dL 163 (191), vL 110 (127), dL/vL ratio 1.48 (1.5), maximum H 50 (59), dL/maximum H 3.25 (3.21), S-1 L 89 (91), L/W ratio 8.1 (7.3), S-2 L 69 (74), L/W ratio 5.5

(5.3), distance S-1-2, 16 (19), dL ratio S-1/2 1.29 (1.23); I-L-6 dL 113 (131), central H 26 (28), dL/central H ratio 4.4 (4.7); L I-L-5/6 ratio 1.44 (1.45).

Female (from KR22 [juvenile?]; in parentheses specimen from KR3) — Idiosoma L 581

(875), W 438 (613); maximum diameter Dgl-4, 30 (27). Coxal shield L 381 (409); Cx-III

W 459 (488); Cx-I+II mL 106 (128), Cx-I+II lL 269 (284). Genital field L/W 151 (198)/161

(199), genital plates L 134-138 (139-145), pregenital sclerite W (99), gonopore L 117 (168), L

Ac-1-3: 45-47 (47-48), 52-56 (52-53), 52-53 (48).

Gnathosoma — Palp total L 395 (403); dL/H, dL/H ratio: P-1, 41/33, 1.24 (39/34, 1.14);

P-2, 86/59, 1.45 (85/64, 1.33); P-3, 103/52, 2.0 (109/53, 2.1); P-4, 125/37, 3.4 (129/38, 3.4);

P-5, 40/17, 2.4 (41/16, 2.5); length ratio P-2/P-4 0.69 (0.66). Gnathosoma vL 172; chelicera total L 290 (290). Egg maximum diameter (n=1) (172).

Legs — I-L-5 dL 242 (255), vL 155 (188), dL/vL ratio 1.57 (1.36), maximum H 73 (66), dL/maximum H 3.3 (3.9), S-1 L 105 (113), L/W ratio 7.5 (8.0), S-2 L 88 (91), L/W ratio 5.2

(5.8), distance S-1-2, 28 (20), dL ratio S-1/2 1.19 (1.24); I-L-6 dL 159 (166), central H 28 (27), dL/central H ratio 5.8 (6.2); L I-L-5/6 ratio 1.52 (1.54).

Etymology — The new species is named after the Tien Shan mountain range from where the new species originates.

Discussion — Due to a similar shape of the palp (male P-2 ventrodistal margin convexly protruding) and a moderate interspace (˂ 20 in ♂, ˂ 30 µm in ♀) between the sword setae of I-L-5, the new species resembles A. kyrgyzicus n. sp. (see above). From the latter species A. tienshanensis n. sp. can be separated in the male by the genital plate being wider than long (longer than wide in A. kyrgyzicus n. sp..; compare figures 6A-B with figures 9A, 10A), a P-2 ventrodistal margin with a rugose surface, a comparatively short ventral setae of P-4 and a stouter I-L-6 (dL/H ˂ 5.0 vs. ˃ 5.0 in A. kyrgyzicus n. sp.).

In the key of Western Palaearctic species provided by Gerecke (2003) the new species were placed close to A. glandulosus (Walter, 1918) . The latter species in the both sexes differ in more enlarged dorsal glandularia (diameter ˃ 30 µm) and I-L-5 more thickened in its distal part (ratio dL/H 2.6–3.0, data taken from Smit et al. 2015), and in the male by very strong and long sword seta on P-4, inserting slightly anterior to proximoventral seta ( Smit et al. 2015).

Atractides issajewi (Sokolow, 1928) from Uzbekistan, a species known only in the male sex, is similar in having a slightly protruding ventral margin of P-2 but differs in the P-4 with the sword seta inserting near proximoventral seta, and by a higher number of setae on the lateral margin of the genital plate ( Sokolow 1940).

Distribution — Kyrgyzstan.

Figures

Figure 9 Atractides tienshanensisn. sp., ♂ holotype, KR22 Karakal, Kyrgyzstan. A – idiosoma, ventral view; B – palp, medial view; C – palp, lateral view; D – I-L-5 and -6. Scale bar = 100 µm.

Figure 10 Atractides tienshanensisn. sp., (♂: A-C – KR3 Ala Archa; ♀: D, G-H – KR22 Karakal, E-F – KR3 Ala Archa, Kyrgyzstan). A-B, D-E – genital field; B – genital field with reduced left Ac-2; C – photograph of ejaculatory complex; F – palp, lateral view; G – palp, medial view; H – I-L-5 and -6. Scale bars = 100 µm.