Systematics, distribution and morphology of the newt parasitic water mites of the subgenus Lurchibates Goldschmidt & Fu, 2011 (Acari, Hydrachnidia Hygrobatidae, Hygrobates Koch, 1837), including the description of four new species and a key to all so far known species Author Goldschmidt, Tom Bavarian State Collection of Zoology, Section Arthropoda varia, Münchhausenstrasse 21, D- 81247 Munich, Germany. Author Nishikawa, Kanto 0000-0002-6274-4959 Graduate School of Global Environmental Studies, Kyoto University, Yoshida Hon-machi, Sakyo-ku, Kyoto 606 - 8501, Japan. nishikawa. kanto. 8 v @ kyoto-u. ac. jp; https: // orcid. org / 0000 - 0002 - 6274 - 4959 & Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu-cho, Sakyo-ku, Kyoto 606 - 8501, Japan. Center for Molecular Biodiversity Research, National Museum of Nature and Science, Tsukuba, 305 - 0005 Japan. s-hiruta @ kahaku. go. jp; https: // orcid. org / 0000 - 0001 - 7890 - 1720 nishikawa.kanto.8v@kyoto-u.ac.jp Author Hiruta, Shimpei F. 0000-0001-7890-1720 s-hiruta@kahaku.go.jp Author Pfingstl, Tobias Institute of Biology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria. Author Jiang, Jian-Ping Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China. Author Shimano, Satoshi Science Research Center, Hosei University. Fujimi 2 - 17 - 1, Chiyoda-ku, Tokyo 102 - 8160, Japan. text Zootaxa 2021 2021-06-11 4985 1 1 36 journal article 4938 10.11646/zootaxa.4985.1.1 e8a47bc6-e0ca-4389-9c90-b23a1e56581f 1175-5326 4929035 4EAFC76B-D4E4-4D96-8D0D-1B24E44975C7 Hygrobates ( Lurchibates ) macrochela sp. nov. Goldschmidt, Nishikawa & Shimano Material examined: Holotype male, slide mounted in glycerine jelly, preparation no. CIB INV 0017, parasitic on Pachytriton inexpectatus ( Amphibia , Caudata , Salamandridae ); newt was collected in China , Guangxi Zhuang Autonomous Region, Jinxiu Yao Autonomous County, Dayaoshan 24°08’1’’ N, 110°11’5.9’’ E, 1140 m a.s.l. on October 10 th 2008 , preserved in 70% ethanol; mite was attached to the fingers of the newt ( CIB GX20081028). Paratypes (as well parasitic on Pachytriton inexpectatus ): Two males ( CIB INV 0019 , 0020 ) from fingers and toes of the same newt ( CIB GX20081028 ), two females ( CIB INV 0018 ) from left hindlimb of the newt ( CIB 200712004 ) collected in China , Guangxi Zhuang Autonomous Region , Ziyuan , Maoershan 25°54’44.3’’ N, 110°27’55.8’’ E, 1651 m a.s.l. on December 12 th 2007 and ( CIB INV 0021 ) from fore- or hindlimb of the newt ( CIB GX20081003 ) collected at same locality as holotype on October 9 th 2008 . Distribution: All specimens of H. ( L. ) macrochela sp. nov. were recorded on Pachytriton inexpectatus from China , Guangxi Zhuang Autonomous Region, China . The new species is at maximum limited to the same distribution as its host, which is so far known from Eastern Guizhou , southwestern and southern Hunan , extreme northwestern Guangdong , and northern and eastern Guangxi , China ( Fig. 54 ). Derivatio nominis: macrochela ; a combination of the words macro , derived from μακρός (makrós) (Greek = large) and chela , χηλή (Greek = claw); named for the fact that the cheliceral claws of the new species are the most massive within the species of Lurchibates . Diagnosis: Anterior coxal group basally broad (compared to most other species of the subgenus), posterior coxal group medially rounded, therefore irregular triangular; male genital field broad apple-shaped, surrounded by rather few setae; female genital plates crescent-shaped, about same length as genital opening (slightly shifted to posterior); palp relatively compact, P-3 ventrally with rather large field of denticles, covering distal half of segment, P-4 relatively short, curved, proximo-ventral extension of P-5 blunt, cone-shaped, large distal claws slightly different in size, small one slender; cheliceral claw curved, characteristically extended in distal half. Description, Male (n = 3): Idiosoma rounded-oval, L/W ratio 1.33 (1.19–1.24), L/W 864 (624–756)/648 (504–636); fused anterior coxae of both sides slightly elongate (Cx-I + II L/W 276 (256–264)/378 (372–382), ratio 0.73 (0.67–0.71)), medio-posterior margin convex, postero-laterally extended by secondary sclerotization (lateral tips small, not reaching medial margin of Cx-III/IV), Cx-I basal broad, W 155 (157–162), Cx-I L/basal W 1.78 (1.62–1.63); gnathosoma broad, posteriorly clearly converging, widely fused with the posterior part of the first coxae, anterior margin of gnathosoma curved ( Fig. 1 ); posterior coxal groups (Cx-III + IV of one side) L/W 216 (229–233)/204 (168–199), laterally closely approached to anterior plates (Cx-II postero-laterally overlapping antero-lateral corners of Cx-III), medially clearly diverging from anterior coxae, medial edges rounded, pointing towards anterior, formed by Cx-IV only, antero-medial and posterior margin irregular curved, Cx-III antero-laterally extended, lateral margin straight, Cx-IV compact, lateral margin convex ( Fig. 1 ); genital field broad apple-shaped (genital plates and pre- and postgenitale seamless fused), anterior with small indentations between fused acetabular plates and pregenitale, posterior with deep, broad rhombic indentation (Ac-2 and Ac-3 posteriorly far extending beyond postgenitale), genital opening elongated-oval, margins nearly straight, genital field L/W 174 (170–180)/246 (240–256); acetabula irregular oval-drop-shaped (Ac-3 kidney-shaped), L/W Ac-1 70 (64–73)/34 (37–40), Ac-2 86 (83–89)/33 (31–34), Ac-3 92 (72–80)/42 (39–42), 17 (19–22) setae (of different size) on each side of plate, irregularly arranged at the margins of the genital plate ( Fig. 1 ); excretory pore slit-shaped; genital skeleton L/W (200–207)/(143–153), compact (L/W ratio (1.35–1.39), shape typical for the subgenus, brachia distalia strong, slightly curved, brachia proximalia strong, distally broadened, parallel to longitudinal axis ( Fig. 2 ); all legs slender, bearing many heavy setae ( Figs. 3–6 ); measurements (L/H) of distal leg segments: I-leg-5 186 (198)/42 (42), I-leg-6 176 (174)/40 (40); II-leg-5 204 (211–220)/42 (44–46), II-leg-6 188 (190–192)/41 (42); III-leg-5 222 (234–240)/47 (44–48), III-leg-6 204 (210–214)/42 (36–44); IV-leg-3 152 (162–172)/65 (54–58), IV-leg-5 229 (244–246)/48 (42– 48), IV-leg-6 216 (222–224)/42 (41–42); chelicerae very strong, with a compact basal segment and short basal groove; cheliceral claws very heavy, strongly curved, sharply pointed, dorsal margin in the distal half extended, with strong serration, medially and laterally striated ( Figs. 7, 8 ); palps strong, rather compact ( Figs. 9, 10 ), dorsal margin of P-2 regularly curved, ventrally without denticles, P-3 ventrally straight with a small field of pointed denticles in the distal half, P-4 relatively short and curved, with a pair of ventral setae in the distal third, distal margin curved; P- 5 with a well developed, blunt cone-shaped ventro-distal projection, dorso-distally P-5 bearing one small, relatively slender distal claw and distally a pair of clearly different, large, strong, pointed, slightly curved claws (medial claws clearly more slender than lateral ones); mouthpart measurements: Chelicera total L 372 (378), H 108 (113–114), L/ H ratio 3.44 (3.35), basal segment L 255 (261), claw L 162 (174–176), basal segment/claw ratio 1.6 (1.5); curvation of cheliceral claw 30° (30°); palp total L 381 (411–414), L/H P-1 35 (33–35)/61 (66–67), P-2 116 (132)/92 (92–94), P-3 71 (78–80)/74 (79–81), P-4 119 (125–127)/49 (52–56), P-5 40 (42)/38 (39–40). FIGURES 1, 2. Hygrobates ( Lurchibates ) macrochela sp. nov. , holotype male, Fig. 1. ventral view of idiosoma; Fig. 2. genital skeleton in anterior view; scale bars = 100 µm. FIGURES 3–10. Hygrobates ( Lurchibates ) macrochela sp. nov. , holotype male, Fig. 3. I-leg, right; Fig. 4. II-leg, right; Fig. 5. III-leg, right; Fig. 6. IV-leg, right; Fig. 7. left chelicera in medial view; Fig. 8. right chelicera in lateral view; Fig. 9. left palp in medial view; Fig. 10. right palp in lateral view (P-1 missing); scale bar = 100 µm. Figure 11 . Hygrobates ( Lurchibates ) macrochela sp. nov. , paratype female, ventral view of idiosoma; scale bar = 100 µm . FIGURES 12–19. Hygrobates ( Lurchibates ) macrochela sp. nov. , paratype female, Fig. 12. I-leg, right; Fig. 13. II-leg, right; Fig. 14. III-leg, right; Fig. 15. IV-leg (terminal segment separated), right; Fig. 16. left chelicera in lateral view; Fig. 17. right chelicera in medial view (slightly broken); Fig. 18. left palp in lateral view; Fig. 19. right palp in medial view; scale bar = 100 µm. Description, Female (n = 2): Idiosoma similar to male, larger, L/W 882–960/600–672, less rounded (L/W ratio 1.43–1.47); unpaired anterior coxal group slightly more compact, basally broader than in males (Cx-I + II L/W 312–342/444–456, ratio 0.70–0.75), basal width Cx-I 197–202; medio- and latero-posterior margin extended by secondary sclerotization, lateral apodemes slightly larger than in males, more hook-shaped; gnathosoma broadly fused with the posterior part of the first coxae, lateral margins straight, posterior converging, anterior margin slightly convex, nearly straight; coxal groups slightly further separated than in males, laterally not overlapping ( Fig. 11 ); posterior coxal groups similar to males, L/W 258–276/216–222, roughly triangular in shape, medial margin formed by Cx-IV ( Fig. 11 ); genital field with strongly sclerotized pre- and postgenitale, genital plates well distant from each other, separated by soft integument, crescent- to kidney-shaped, anteriorly and posteriorly rounded, about as long as genital opening, however slightly shifted to posterior, total genital field L/W 204–206/306–312, individual genital plate L/W 162–169/73; Ac-1 irregularly-oval, L/W 64–66/36–39, Ac-2 elongated-oval, L/W 83–89/36–42, Ac-3 irregularly triangular, apically pointed, L/W 66–70/57–66); 18–21 setae arranged mainly at the anterior and posterior margins of the genital plates ( Fig. 11 ); egg diameter 150, number of eggs five to 53 (four ovigerous females are not part of the type series); legs similar to males, slightly more slender ( Figs. 12–15 ); measurements of distal leg segments: L/H I-leg-5 228–235/44–52, I-leg-6 180–198/32–42; II-leg-5 246–252/48–52, II-leg-6 196–210/42–43; III-leg-5 264–281/50–55, III-leg-6 228–240/42–44; IV-leg-3 186–187/62–66, IV-leg-5 274–294/42–48, IV-leg-6 246–252/42–42; chelicerae of similar shape as in males, slightly larger ( Figs. 16, 17 ); palps similar to males, slightly less compact ( Figs. 18, 19 ); mouthpart measurements: Chelicera total L 468–511, H 138–144, L/H ratio 3.4–3.6, basal segment L 315–355, claw L 212–244, basal segment/claw ratio 1.5; cheliceral claw curve 30–31°; palp total L 472–501, L/H P-1 40–42/80–82, P-2 155–165/106–115, P-3 78–89/89–96, P-4 146–157/59–66, P-5 49–52/47.