Water mites of the genus Brachypoda Lebert, 1879 (Acari: Hydrachnidia: Aturidae) from South Korea and the Russian Far East Author Pešić, Vladimir Author Semenchenko, Ksenia text Zootaxa 2014 3753 4 335 346 journal article 46728 10.11646/zootaxa.3753.4.3 0dad7567-0ab1-4f7f-9f9a-299ef14f50f0 1175-5326 231432 1A03E4AF-AC8F-4227-9225-23D1D78115DA Brachypoda rossica sp. n. ( Figs. 6A–C , 7A–F , 8A–E ) Material examined . Holotype : male (300-kas IBSS ), RUSSIA : Amurskaya Province, Magdagachinsky District, Levaya Burinda River, 53°27.731'N , 125°07.808'E ; depth 0,2– 1 m ; substrates: coarse-grained sand, 21.vii.2006 , Semenchenko & Sidorov. Paratypes : three females (308–310-kas– IBSS ), same data as holotype . Diagnosis. Male. Cauda slightly narrowed posteriorly, posterior margin of idiosoma almost straight; a distinct ridge extending anterolaterally from genital field but not reaching lateral idiosoma margins at level of IV-L insertions; distance Ac-2–3 about two diameters of Ac-1; IV-L-4 with short and pointed dorsodistal extension. Female. Anterior margin of Cx-I ending posterior to level of frontal idiosoma margin; number of swimming setae: II-L-5, 3, III-L-5, 3, IV-L-5, 3–4. FIGURE 6A–C . Brachypoda rossica sp. n. , male: A = dorsal shield; B = idiosoma, ventral view; C = palp. Scale bars = 100 Μm (A–B), 25 Μm (C). FIGURE 7A–F . Brachypoda rossica sp. n. , male: A = II-L-5 and -6; B = III-L-5 and -6; C = III-L-3–6; D = claw of I-L; E = claw of III-L; F = claw of IV-L. Scale bars = 50 Μm (C), 25 Μm (A–B, D–F). Male ( holotype ): Idiosoma L/W 554/416; dorsal shield L/W 501/409, idiosoma slightly tapering posteriorly, with rounded frontal and straight posterior margins ( Fig. 6A ); major portion of body sclerotized, except broad part of interscutal membrane in front; excretory pore and flanking glandularia on dorsal shield, near posterior margin. Tip of Cx-I not reaching frontal idiosoma margin; distance tip Cx-I – gonopore 488; gnathosomal bay L 112; distance between IV-L insertions 132; a distinct ridge extending anterolaterally from genital field ( Fig. 6B ); gonopore L/W 70/13, laterally flanked by the acetabula arranged in a weakly curved line, and numerous fine setae – most of these at anterior edge, 8–10 long hairs at the anterolateral margin of genital field, distance between Ac-2 and -3 about two diameters of Ac-1. Gnathosoma vL 67, L with apodemes 100; chelicera total L 113, basal segment L 78, claw L 35. Palp ( Fig. 6C ): total L 284, L/H, ratio L/H: P-1, 38/26, 1.45; P-2, 65/54, 1.2; P-3, 51/35, 1.46; P-4, 103/46, 2.2; P-5, 27/12, 2.25; P-1 with one dorsal seta; P-2 with anteroventral projection; P-3 ventral margin concave; P-4 proximally narrow, ventral margin convexly protruding, with one stout and one finer seta of equal length in the centre, dorsal surface with numerous solenidions. Legs: number of swimming setae: II-L-5, 4 (not exceeding tip of II-L-6, see Fig. 7A ), III-L-5, 3 (shorter than L of III-L-6, see Fig. 7B ); III-L-6 ventral and dorsal margins strongly diverging from base to tip ( Fig. 7B ); IV-L-4 distally strongly enlarged ( Fig. 7C ), here bearing four setae, two of these located ventrodistally, heavy and modified as shown in Fig. 7C , forming a short and pointed extension projecting over base of IV-L-5, with two heavy apical setae (one spatula-like and one slender with a denticulated margin), IV-L-4 L/H 108/51, ratio 2.1; IV-L-5 proximally narrow, ventral margin with scattered short setae, distal margin with five strong setae, three of these very long, whip-like, extending beyond tip of IV-L- 6, IV-L-5 L/H 181/65, ratio 2.7; IV-L-6 L/H 181/32, ratio 5.6; IV-L-6 slightly curved, ventrally with a line of longer setae. Claws of I–II-L ( Fig. 7D ) with well developed blade and 3 clawlets: dorsal and ventral clawlets short, central clawlet long, ventral margin of claw blade concave; claws of III-L ( Fig. 7E ) with 3 clawlets: ventral clawlet short, dorsal clawlet reduced to a small denticle, central clawlet long, ventral margin of claw blade convex; claws of IV-L modified as given in Fig. 7F , claws without dorsal clawlet and ventral clawlet reduced to a small denticle, anterior claw longer than posterior claw. Female ( paratypes ): Idiosoma L/W 554–561/475–495; dorsal shield L/W 462–488/363–376 µm, excretory pore and flanking glandularia on transversal plate posterior to dorsal shield ( Fig. 8A ). Tip of Cx-I not extending to frontal idiosoma margin ( Fig. 8B ); L of ventral shield from tip Cx-I 442–443; gnathosomal bay L 115–118; distance between IV-L insertions 211–224. Genital plates L/W 76–84/35–41, transversal, each with 3 acetabula and 3–4 short, fine setae. Gnathosoma vL 80, L with apodemes 100; chelicera total L 121, basal segment L 86, claw L 35. Palp ( Fig. 8C ): total L 242–251, L/H, ratio L/H: P-1, 33–35/21–22, 1.6; P-2, 57–59/40–48, 1.2–1.4; P-3, 46–47/ 27–35, 1.3–1.7; P-4, 81–84/30–35, 2.4–2.7; P-5, 26–27/10–12, 2.2–2.6. Legs: number of swimming setae: II-L-5, 3, III-L-5, 3, IV-L-5, 3–4; IV-L unmodified, claws with 3 clawlets ( Figs. 8D, E ), IV-L-4 L/H 97–110/30–35, ratio 3.1–3.2; IV-L-5 L/H 119–135/23–32, ratio 4.2–5.2; IV-L-6 L/H 115–118/23–26, ratio 4.5–5.0. FIGURE 8A–E . Brachypoda rossica sp. n. , female: A = dorsal shield; B = idiosoma, ventral view; C = palp; D = IV-L-4–6; E = claw of IV-L. Scale bars = 100 Μm (A–B, D), 25 Μm (C, E). Etymology. The species is named after the country where it was collected ( Russia ). Discussion. Tuzovskij (2004) introduced the new subgenus Eubrachypoda to accommodate B. japonensis Tuzovskij, 2004 , a species described from Lake Biwa in Japan . Due to the morphology of male genital field (set off from posterior margin), Eubrachypoda Tuzovskij, 2004 , resembles Ocybrachypoda Cook, 1974 and Brachypoda s. str. Lebert, 1879. The later subgenus differs in the male in the posterior margin of Cx-IV on both sides forming a curved ridge extending from genital field to the level of IV-L insertions, and the acetabula arranged in a triangle. Ocybrachypoda Cook differs in IV-L-4 lacking a pronounced distal projection. The new species from the Far East of Russia closely resembles B. japonensis Tuzovskij, 2004 , but has partially developed ridges extending anterolaterally from genital field, not reaching lateral margins at level of IV-L insertions, suggesting that this character varies and cannot be used in subgeneric classification. Further differences with B. japonensis (in parentheses) include the following characters: cauda slightly narrowed posteriorly, with almost straight posterior margin (cauda strongly narrowed posteriorly, with rounded posterior margin); distance Ac-2–3 greater than width of Ac-1 (equal to width of Ac-1); dorsodistal extension on IV-L-4 shorter and pointed (longer and slender, fingershaped). Habitat. A river with pebble and coarse-grained sand ( Fig. 9E ). Distribution. Far East of Russia , known only from the locus typicus .