A new species of the genus Atractides Koch, 1837 from Turkey (Acari: Hydrachnidia: Hygrobatidae) Author Pešić, Vladimir Department of Biology, University of Montenegro, Cetinjski put b. b., 81000 Podgorica, Montenegro. Author Smit, Harry Naturalis Biodiversity Center, P. O. Box 9517, 2300 RA Leiden, the Netherlands. * Corresponding author. E-mail: vladopesic @ gmail. com Author . Author .,. Author .,. Author K. Author A,. Author . Author . Author ., P Author . Author . text Ecologica Montenegrina 2021 2021-06-22 43 44 50 http://dx.doi.org/10.37828/em.2021.43.6 journal article 10.37828/em.2021.43.6 2336-9744 13233513 urn:lsid:zoobank.org:pub:4D9D4FBA-04BF-4826-9E53-92D363E77AF9 Atractides ( Atractides ) concavus sp. nov. https://zoobank.org/ urn:lsid:zoobank.org:act: EE94AC4E-09C3-4839-96CF-D471515C942B Figs. 1-4 Type material — Holotype ♂ , dissected and slide mounted ( RMNH ), Turkey , Afyonkarahisar Province , Akdağ stream near Sandikli , 25.06.2006 leg. F. Aşçı. Paratypes : 14 ♂ , 20 ♀ , same site and data as the holotype, leg. F. Aşçı , 2 ♂ , 1 ♀ , dissected and slide mounted ( RMNH ) . Diagnosis — Integument finely striated, muscle insertions and excretory pore unsclerotized; Vgl-1/2 separate. Male genital field anteriorly indented, anteromedial indentation with a peg-shaped fissure. Palp with strong sexual dimorphism (male P-2 with a strongly developed distal extension, female P-2 with a slightly convex ventrodistal margin); I-L-5 slender, ratio dL/maximum H 3.8–4.2; I-L-6 slender, ratio dL/central H 6.0–6.8. Description. General features — Integument fnely striated; muscle insertions unsclerotized; dorsal glandularia diameter 30-40 µm. Mediocaudal margin Cx-I slightly convex, apodemes of Cx-II in an obtuse angle. Acetabula in triangular arrangement. Excretory pore smooth; Vgl-1 not fused to Vgl-2 ( Fig. 1A ). Palp with strong sexual dimorphism in shape of P-2 and P-4, in both sexes with a strong and long sword seta on P-4. I-L-5 long and slender, equally enlarged from the base to the insertion of S-1-2 setae, S-1 slightly curved and slender, bluntly pointed; S-2 shorter, proximally enlarged and pointed; I-L-6 slender (L/central H ratio 6.0–6.8), slightly inflated proximally, equally curved and narrowed from base to tip ( Fig. 2C ); distomedial margins of IV-L-4/5 equally convex, only slightly extending beyond the base of subsequent segments. Male — Setae of dorsal glandularia very long, in particular those of Dgl-3 and –4 ( Fig. 3A ); Vgl- 3 in older specimens fused to posterior margin of Cx-IV ( Fig. 1B ). Anterior and posterior margin of genital field indented, V-shaped medial indentation with a peg-shaped fissure ( Figs. 1 A-B, 4A-C); acetabula relatively large, subtriangular. P-2 with a strongly developed distal extension consisting of a rounded medial hump with rugose margin and an irregularly convex lateral thickening; P-4 stout, with a dense cover of fine dorsal setae, maximum H on the level of the proximoventral seta; sword seta inserting slightly anterior to proximoventral seta ( Figs. 2 A-B). Female — Genital field with a short gonopore, pregenital sclerite small; genital plates nearly semi-circular, Ac-3 much enlarged. P-2 with a slightly convex ventrodistal margin; P-3 ventral margin concave; P-4 slender, ventral margin slightly protruding near proximoventral seta, sword seta strong and long, inserted between ventral setae ( Fig. 3D ). Measurements. Male ( holotype , in parentheses measurements of paratype , n = 1) — Idiosoma L 625 (666), W 545 (563); maximum diameter Dgl-3, (36). Coxal shield L 384 (388); Cx-III W 444 (466); Cx-I+II mL 136 (133), Cx-I+II lL 286 (288). Genital field L/W 127 (136)/173 (170) ratio 0.73 (0.8), L Ac-1-3: 45 (51), 56 (59), 61 (63). Ejaculatory complex L 127 (119). Gnathosoma — palp total L 354 (357); dL/H, dL/H ratio: P-1, 34/34, 1.0 (34/34, 1.0); P-2, 80/65, 1.22 (78/70, 1.1); P-3, 84/58, 1.47 (88/58, 1.52); P-4, 113/43, 2.6 (109/45, 2.4); P-5, 43/17, 2.5 (48/16, 2.9); length ratio P-2/P-4 0.71 (0.71). Gnathosoma vL 150; chelicera total L 266 (256). Legs — I-L-5 dL 213 (213), vL 149 (152), dL/vL ratio 1.43 (1.41), maximum H 51 (56), dL/maximum H 4.18 (3.84), S-1 L 108 (102), L/W ratio 10.6 (10.1), S-2 L 88 (85), L/W ratio 5.6 (6.0), distance S-1-2, 20 (19), dL ratio S-1/2 1.23 (1.19); I-L-6 dL 141 (142), central H 23 (22), dL/central H ratio 6.0 (6.5); L I-L-5/6 ratio 1.51 (1.5). Female — Idiosoma L 788, W 613; maximum diameter Dgl-3, 33. Coxal shield L 431; Cx-III W 531; Cx-I+II mL 138, Cx-I+II Ll 300. Genital field L/W 169/191, genital plates L 147, pregenital sclerite W 53, gonopore L 125, L Ac-1-3: 56, 59, 70. Gnathosoma — palp total L 464; dL/H, dL/H ratio: P-1, 39/38, 1.04; P-2, 100/70, 1.4; P-3, 126/52, 2.4 1.9; P-4, 143/39, 3.7; P-5, 56/20, 2.8; length ratio P-2/P-4 0.7. Gnathosoma vL 178; chelicera total L 355. Legs — I-L-5 dL 266, vL 180, dL/vL ratio 1.48, maximum H 64, dL/maximum H 4.18, S-1 L 129, L/W ratio 10.3, S-2 L 105, L/W ratio 6.1, distance S-1-2, 34, dL ratio S-1/2 1.23; I-L-6 dL 181, central H 27, dL/central H ratio 6.8; L I-L-5/6 ratio 1.47. Etymology — The new species is named after the indentation of the male genital field. Discussion — The new species is closely related to Atractides nodipalpis Thor, 1899 (striated integument, unsclerotized muscle insertions, males with anteriorly indented genital field, P-2 with distoventral extension and P-4 ventral margin projecting, distomedial margins of IV-L-4/5 equally convex, only slightly extending beyond the base of subsequent segments). The latter species differ from A . concavus sp. nov . in the shape of genital field (anterior margin of male genital plate deeply indented, often with a small projection in the centre of indentation vs . anteromedial indentation of male genital plate with a peg-shaped fissure in A. concavus sp. nov . ). Figure 1 . Atractides concavus sp. nov . , ♂ (A, holotype, B, paratype). A – idiosoma, ventral view; B – genital field and posterior margin of Cx-IV. Scale bar = 100 µm. Figure 2 . Atractides concavus sp. nov . , ♂ (A, C holotype, B, paratype). A – palp, medial view; B – palp, lateral view; C – I-L-5 and -6. Scale bar = 100 µm. Figure 3 . Atractides concavus sp. nov . , (A, ♂; B-D, ♀ paratype). A – idiosoma, dorsal view (inset: Dgl-3, 2X); B – genital field; C – I-L-5 and -6; D – palp, medial view. Scale bars = 100 µm. The new species is likely conspecific with Atractides nodipalpoides Aşçı, Boyaci & Özkan, 2011 , a species described by Aşçı et al . (2011) on the basis of two males collected in the neighbouring Konya Province in Central Anatolia . Based on the illustrations of the original description of the latter species ( Aşçı et al . 2011 ), both species share a characteristic shape of the anteromedial indentation of the male genital plate and similar morphology of palps. However, no location of the holotype is mentioned in the paper of Aşçı et al . (2011) (no museum or institute), which makes the name invalid (International Code of Zoological Nomenclature, 1999 , Art. 16.4.2). Distribution — Turkey .