Atractides (Atractides) alaarchaensis, Pešić & Smit, 2018

Pešić, Vladimir & Smit, Harry, 2018, A checklist of the water mites of Central Asia with description of six new species (Acari, Hydrachnidia) from Kyrgyzstan, Acarologia 58 (1), pp. 165-185 : 175-180

Atractides (Atractides) alaarchaensis n. sp. ( Figure 5-7 )

Zoobank: 51EA2777-8191-4C77-876B-0 ACE 5B269136

Type material — Holotype male ( RMNH), Kyrgyzstan, KR3 Ala Archa NP, rheocrenic spring and first order stream, 42°36.202’N, 074°28.837’E, 1899 m asl., 9.vii.2013, leg. Pešić & Smit, dissected and slide mounted. Paratypes: 12/27/3, same data as holotype, 2/1/1, dissected and slide mounted.

Diagnosis — Coxae without sexual dimorphism (in both sexes Cx-I+II close to Cx-III+IV at their touching edges, but not forming a coxal shield, Vgl-3 not fused to Cx-IV); P-2 ventral margin convex, without distal projection, P-3 with one seta each on medial and lateral surface extending beyond ventral margin of segment; in male S-1-2 separation 19-21 μm.

Description — Adults: General features — Integument striated, muscle insertions unsclerotized. Excretory pore smooth; Vgl-1 not fused to Vgl-2. Palp with weak sexual dimorphism, P-2 ventral margin convex, without projection, P-3 with one seta each on medial and lateral surface, P-4 sword seta between ventral setae. I-L-5 with S-1 and -2 separated, S-1 longish and blunt, S-2 pointed and thicker than S-1, I-L-6 curved, basally thickened, from the centre to the claw furrow with parallel dorsal and ventral margins ( Figure 5A ). Male: Genital plate anterior margin equally convex, with a narrow border of secondary sclerotization, posterior margin indented, acetabula in an obtuse triangle ( Figure 5E ); P-2 ventrodistally convex, P-4 thickened, ventral margin slightly projecting near insertion of proximoventral seta ( Figures 5 C-D). Female. Acetabula in a weakly curved line ( Figure 6D ); P-2 ventral margin slightly convex, P-4 slender than in male ( Figure 6C ).

Deutonymph: Provisional genital field with two pairs of acetabula ( Figure 7C ); P-2 ventral margin convex, P-3 without seta on medial and lateral surface.

Measurements — Male (holotype; in parentheses paratypes, n = 2) — Idiosoma L 628 (631-656), W 416 (425-475); maximum diameter Dgl 26 (27-28); coxal field: L 328 (339-359), Cx-III W 347 (344-375), mL 113 (113-116), lL 204 (216); genital field L/W 117 (120-128)/123 (127-134), maximum diameter Ac 1-3: 38 (41-45), 39 (38-46), 40 (39-46); ejaculatory complex L 111 (125).

Gnathosoma — palp total L 307 (304-317); dL/H, dL/H ratio: P-1, 33/28, 1.17 (31-34/28- 30, 1.1-1.2); P-2, 66/47, 1.4 (66/48, 1.36-1.37); P-3, 77/41, 1.89 (75-77/41, 1.85-1.89); P-4, 97/27, 3.6 (101-106/25, 4.0-4.2); P-5, 34/12, 2.9 (31-34/13, 2.5-2.7); L ratio P-2/P-4 0.68 (0.63-0.65). Gnathosomal base vL (106-111); chelicera total L (212-213).

Legs — I-L-5 dL 184 (186-192), vL 123 (119-126), dL/vL ratio 1.5 (1.53-1.56), maximum H 47 (47-52), dL/maximum H 3.9 (3.7-4.0), S-1 L 86 (89-91), L/W ratio 9.2 (9.0-9.5), S-2 L 72 (75-78), L/W ratio 6.2 (5.7-6.2), distance S-1-2 19 (20-21), L ratio S-1/2 1.19 (1.17-1.19); I-L-6 L 129 (128-130), central H 22 (20-21), L/central H ratio 5.9 (6.1-6.4); L ratio I-L-5/6 1.43 (1.45-1.48).

Female (paratype, n = 1) — Idiosoma L 781, W 578; maximum diameter Dgl 27; coxal field: L 403; Cx-III W 456; Cx-I+II mL 141, lL 267; genital field L/W 182/180, genital plates L 130-136, pregenital sclerite W 81, maximum diameter Ac 1-3: 45, 42, 44.

Gnathosoma — palp total L 391; dL/H, dL/H ratio: P-1, 37/34, 1.07; P-2, 84/56, 1.5; P-3, 105/46, 2.28; P-4, 125/30, 4.2; P-5, 42/16, 2.7; L ratio P-2/P-4 0.68. Gnathosomal base vL

128; chelicera total L 266.

Legs — I-L-5 dL 231, vL 148, dL/vL ratio 1.57, maximum H 59, dL/maximum H 3.9, S-1 L 113, L/W ratio 10.6, S-2 L 89, L/W ratio 6.8, distance S-1-2 31, L ratio S-1/2 1.26; I-L-6 L 148, central H 23, L/central H ratio 6.3; L ratio I-L-5/6, 1.56.

Deutonymph (n = 1) — Idiosoma L 409, W 298; provisionally genital field L/W 63/80, ratio 0.79.

Palp: total L 219; dL/H, dL/H ratio: P-1, 23/22, 1.1; P-2, 45/34, 1.35; P-3, 56/28, 2.0; P-4, 69/19, 3.7; P-5, 26/9, 2.75; L ratio P-2/P-4 0.66.

Legs — I-L-5 dL 144, vL 97, dL/vL ratio 1.49, maximum H 41, dL/maximum H 3.55, S-1 L 69, L/W ratio 7.3, S-2 L 63, L/W ratio 5.7, distance S-1-2 13, L ratio S-1/2 1.1; I-L-6 L 100, central H 19, L/central H ratio 5.3; L ratio I-L-5/6, 1.44.

Discussion — Due to a similar shape of palp and I-L-5 and -6, the new species is closely related to Atractides sonkulensis n. sp. (see below) and differs from all other species in having one seta each on medial and lateral surface of P-3. Atractides sonkulensis n. sp. differs in the male in generally smaller dimensions of idiosoma, I-L-5/6 and palps (e.g., idiosoma L <500 μm, -L-5 dL 145, palp total L <300 μm), a coxal field merged to an unique plate including Vgl-3, a nearly straight ventral margin of P-2 and a shorter S-1/2 interspace (9-10 μm). In the female A. sonkulensis n. sp. differs in a smaller dimensions of medial suture line of Cx-I+II, genital plates and acetabula, and a relatively longer I-L-6 (L ratio I-L-5/6 1.4).

Etymology — Named after the National Park where the new species was found.

Distribution — Kyrgyzstan; known only from the locus typicus ( Figure 10A ).

Figures

Figure 5 Atractides alaarchaensis n. sp., male holotype: A – idiosoma, ventral view; B – I-L-5 and -6; C – palp, medial view; D – palp, lateral view; E – genital field. Scale bars = 100 μm.

Figure 6 Atractides alaarchaensis n. sp., female paratype: A – coxal field; B – I-L-5 and -6; C – palp, lateral view; D – genital field. Scale bars = 100 μm.

Figure 7 Atractides alaarchaensis n. sp., deutonymph: A – I-L-5 and -6; B – palp, medial view; C – genital field. Scale bars = 100 μm.

Figure 10 Photographs of sampling sites: A – KR3, Ala Archa NP, spring outlet (locus typicusof Atractides alaarchaensis n. sp.); B – KR32, stream near Son Kul lake (locus typicusof Atractides sonkulensisn. sp.); C – KR10, spring in Grigorievka canyon (locus typicusof Atractides grigorievkan. sp.); D – KR8, Chon-Kemin NP, upper part of stream near Ashu resort (locus typicusof Torrenticola kyrgyzican. sp.); E – KR15, river on the road to May Saz Pass (locus typicusof Wandesia albertii n. sp.); F – KR22, stream in Karakal region (locus typicusof Atractides manasi n. sp.); G – KR23, rheohelocrenic spring in Karakal region (sampling site of Atractides grigorievkan. sp.); H – KR31, river near Son Kol Lake (sampling site of Atractides sonkulensisn. sp.).