Hygrobates (Lurchibates) malosimilis, Goldschmidt & Nishikawa & Hiruta & Pfingstl & Jiang & Shimano, 2021

Goldschmidt, Tom, Nishikawa, Kanto, Hiruta, Shimpei F., Pfingstl, Tobias, Jiang, Jian-Ping & Shimano, Satoshi, 2021, 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, Zootaxa 4985 (1), pp. 1-36 : 8-10

Hygrobates (Lurchibates) malosimilis sp. nov. Goldschmidt, Nishikawa & Shimano

Material examined: Holotype male, slide mounted in glycerine jelly, preparation no. CIB INV 0022, parasitic on Pachytriton inexpectatus ( Amphibia, Caudata , Salamandridae ); newt was collected in China, Guangxi Zhuang Autonomous Region, Jinxiu Yao Autonomous County, Mt. Dayao 24°06’27’’ N, 110°13’52’’ E, 1210 m a.s.l. on September 10 th 2008, preserved in 70% ethanol; mite was attached to the hindlimb of the newt ( CIB GX20081008).

Distribution: The only specimen of H. (L.) malosimilis sp. nov. was collected from Pachytriton inexpectatus from 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.

Derivatio nominis: malosimilis ; derived from malum (Latin = apple) and similis (Latin = similar); named for the apple-shaped male genital field.

Diagnosis (only male): Idiosoma relatively small; anterior coxal group narrow, very slender, basally of intermediate width (compared to most other species of the subgenus), regularly rounded; posterior coxal group medially pointed, very irregular triangular; male genital field apple-shaped; palp relatively compact, P-3 ventro-distally with a patch of denticles, P-4 relatively short, slightly curved, proximo-ventral extension of P-5 blunt, flat cone-shaped, large distal claws of different size (medial smaller), smaller one slender; cheliceral claw curved, extended in distal half.

Description, Male (n = 1): Idiosoma rounded-oval, L/W ratio 1.23, L/W 684/558; fused anterior coxae of both sides slender, narrow triangular, Cx-I + II L/W 264/324, ratio 0.81, secondary sclerotization at medio-posterior margin rather small (posteriorly forming a regular curve, lateral apodemes oriented towards antero-lateral); Cx-I basal width 139, gnathosoma slender, posteriorly only slightly and regularly converging, lateral separation posteriorly only reaching slightly more than half the length of anterior coxal group, widely fused with the posterior part of the first coxae, anterior tip of gnathosoma slightly projecting, anterior margin straight to concave ( Fig. 20 ); posterior coxal groups (Cx-III + Cx-IV of one side) L/W 222/174, anterior and posterior coxal groups laterally very close, medially diverging; posterior coxae irregularly triangular, medial edges pointed, formed by Cx-IV only, anterior and posterior margin heavily undulating, lateral margin slightly undulating, nearly parallel to longitudinal axis ( Fig. 20 ); genital field apple-shaped, anteriorly nose-like pointed, posteriorly with broad, deep, apically rounded indentation, with 17 pairs of setae irregularly arranged at outer margin and laterally beneath elongate-oval genital opening ( Fig. 20 ), genital field L/W 162/210; Ac-1 irregularly drop-shaped, L/W 63/31, Ac-2 lenticular, L/W 77/32, Ac-3 irregularly rectangular drop-shaped, L/W 70/42; genital skeleton partly distorted, L/W 207/150 as far as visible brachia distalia strong, brachia proximalia strong, parallel to longitudinal axis ( Fig. 21 ); all legs slender (especially segments 4–6), bearing several heavy setae, mainly distally at most segments ( Figs. 22–25 ); measurements (L/H) of distal leg segments: I-leg-5 186/40, I-leg-6 158/38; II-leg-5 198/42, II-leg-6 180/42; III-leg-5 216/43, III-leg-6 200/42; IV-leg-3 148/50, IV-leg-5, 228)/41, IV-leg-6 212/40; chelicerae very strong, with a relatively short, high basal segment and mid-sized 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. 26, 27 ); palps relatively compact ( Figs. 28, 29 ), P-2 dorsally regularly curved, ventral margin slightly concave, without denticles, ventro-distal corner of P- 3 rounded, distal half with small field of denticles, P-4 relatively short, slightly curved, with a pair of ventral setae near ventro-distal corner, distal margin convex, rotated ventrally, P-5 with a well developed, blunt cone-shaped ventro-distal projection, dorso-distal seta relatively slender, distal claws clearly different, medial one slender, slightly curved, lateral one clearly stronger, nearly rectangularly hooked; mouthpart measurements: Chelicera total L 342, H 104, L/H ratio 3.3, basal segment L 254, claw L 160, basal segment/claw ratio 1.6; curvation of cheliceral claw 30°, palp total L 376, L/H P-1 33/61, P-2 110/82, P-3 73/67, P-4 118/49, P-5 42/38.

Female (unknown)

Figures

FIGURES 20, 21. Hygrobates (Lurchibates) malosimilis sp. nov., holotype male, Fig. 20. ventral view of idiosoma; Fig. 21. genital skeleton in anterior view (slightly twisted); scale bars = 100 µm.

FIGURES 22–29. Hygrobates (Lurchibates) malosimilis sp. nov., holotype male, Fig. 22. I-leg, right; Fig. 23. II-leg, right; Fig. 24. III-leg, right; Fig. 25. IV-leg, right; Fig. 26. right chelicera in lateral view; Fig. 27. left chelicera in medial view (partly broken); Fig. 28. left palp in medial view; Fig. 29. right palp in lateral view; scale bars = 100 µm.