Torrenticola dbgurungi, PešićK & K & K, 2022

PešićK, Vladimir, K, Harry Smit & K, Mer Man Gurung, 2022, Torrenticolid water mites of Bhutan. Genera Torrenticola Piersig, 1896 and Neoatractides Lundblad, 1941 (Acari: Hydrachnidia: Torrenticolidae), Acarologia 1941 (3), pp. 821-860 : 846-850

Torrenticola dbgurungi sp. nov.

Zoobank: 6D1A6787-A6AC-4C70-9A01-F18E30530573

Figures 17, 18, 19A–G

Material examined — Holotype ♂ dissected and slide mounted, Bhutan, MG8 Dangdung Chhu , 27.33461°N, 90.59562°E, 1039 m asl, 30.x.2021 . Paratypes: 2♂, 1♀, same data as the holotype, 1♂, 1♀ dissected and slide mounted; 1♂, MG 8 Dangdung Chhu, 27.33461°N, 90.59562°E, 1039 m asl, 5.v.2021, dissected and slide mounted; 4 ♂ (2 of them juveniles),

1♀, MG 9 Kartigang Chhu, 27.27896°N, 90.63088°E, 1456 m asl, 7.v.2021, 1♂, dissected and slide mounted; MG 9 Kartigang Chhu, 27.27896°N, 90.63088°E, 1456 m asl, 1.xi.2021, 1♀, dissected and slide mounted.

Diagnosis — Medial suture line of Cx-II+III relatively short; area of primary sclerotization of the dorsal plate with four dorsoglandularia; Cx-IV extended posterior to the genital flaps in both sexes; ejaculatory complex with poorly developed anterior keel, proximal chamber relatively large.

Description — General features – Idiosoma oval; dorsal shield without a colour pattern (as photographed in Figures 19A, B, D); area of primary sclerotization of the dorsal plate with four dorsoglandularia; gnathosomal bay U-shaped, proximally rounded; Cxgl-4 subapical; medial suture line of Cx-II+III relatively short; suture lines of Cx-IV in both sexes distinctly extending posteriorly beyond posterior margin of genital field, laterally curved; excretory pore and Vgl-2 on the the line of primary sclerotization, excretory pore on the level of Vgl-2; gnathosomal ventral margin curved, rostrum almost equal to or less than depth of gnathosoma; P-2 longer than P-4; P-2 ventral margin straight, P-2 and P-3 ventrodistal protrusions bluntly pointed, P-4 with a ventral tubercle bearing one long and three shorter setae ( Figure 17C). I-L-6 stout ( Figure 17E). Male – Medial suture line of Cx-II+III relatively short; genital field with obtuse, but distinct anterior angles, posteriorly parabola-shaped; ejaculatory complex with poorly developed anterior keel, proximal chamber relatively large ( Figures 19C, G). Female – Genital field wider than in male and slightly tapering posteriorly.

Measurements. Male (holotype) – Idiosoma (ventral view: Figure 17B) L 794, W 563; dorsal shield ( Figure 17A) L 607, W 481, L/W ratio 1.26; dorsal plate L 563; shoulder plate

L 203–206, W 77–81, L/W ratio 2.5–2.7; frontal plate L 134–138, W 69, L/W ratio 1.95–2.0; shoulder/frontal plate L 1.5. Gnathosomal bay L 147, Cx-I total L 328, Cx-I mL 178, Cx-II+III

mL 78; ratio Cx-I L/Cx-II+III mL 4.2; Cx-I mL/Cx-II+III mL 2.3. Genital field L/W 163/128,

ratio 1.28; distance genital field-excretory pore 150, genital field-caudal idiosoma margin 203. Ejaculatory complex L 244. Gnathosoma vL 281, chelicera L 322; palp total L 261, dL/H,

dL/H ratio: P-1, 28/31, 0.9; P-2, 83/49, 1.7; P-3, 56/44, 1.3; P-4, 75/31, 2.4; P-5, 19/13, 1.5; L

ratio P-2/P-4 1.1. dL of I-L-2–6: 79, 80, 97, 108, 111; I-L-6 H 52; dL/H I-L-6 ratio 2.15.

Female (paratype from Dangdung Chhu, n = 1) – Idiosoma (ventral view: Figure 18B) L 893, W 650; dorsal shield ( Figure 18A) L 728, W 563, L/W ratio 1.29; dorsal plate L 675; shoulder plate L 228, W 84, L/W ratio 2.7; frontal plate L 159–163, W 75, L/W ratio 2.1–2.2; shoulder/frontal plate L 1.4–1.43. Gnathosomal bay L 175, Cx-I total L 359, Cx-I mL 181, Cx-II+III mL 45; ratio Cx-I L/Cx-II+III mL 8.0; Cx-I mL/Cx-II+III mL 4.0. Genital field L/W 191/163, ratio 1.17; distance genital field-excretory pore 206, genital field-caudal idiosoma margin 272. Gnathosoma vL 322; palp total L 292, dL/H, dL/H ratio: P-1, 31/33, 0.95; P-2,

95/53, 1.79; P-3, 66/50, 1.3; P-4, 83/34, 2.4; P-5, 17/13, 1.3; L ratio P-2/P-4 1.15. dL of

I-L-4–6: 111, 112, 119; I-L-6 H 47; dL/H I-L-6 ratio 2.5.

Etymology — The species is named after Prof. Dhan Bdr Gurung (College of Natural Resources, Royal University of Bhutan) in appreciation of his work on the freshwater fishes of Bhutan.

Discussion — In regard to a short median suture line of Cx-II+III and Cx-IV extended posterior to the genital flaps in both sexes, the new species resembles Torrenticola bhutana Pešić & Smit, 2007 . The latter species can easily be separated by the elongated gnathosomal rostrum and the characteristic shape of the ejaculatory complex (see Figure 1G).

Torrenticola dentipalpis Jin, 1997 a species described from a stream in Mengla, Yunnan province, China ( Jin 1997) is similar in shape of the gnathosoma with a rostrum shorter than width of gnathosoma, and Cx-IV extended posterior to the genital flaps, but differs in I-L-6 not extended (see Figure 80H in Jin 1997) as in the new species from Bhutan, and the dorsal plate bears two dorsoglandularia (Figure 80E in Jin 1997) instead of four dorsoglandularia as in the new species from Bhutan.

Remarks — In one female specimen from Dangdung Chhu the palp has two setae on ventral projection of P-2 ( Figure 18D), a character we consider as an individual aberration.

Distribution — Bhutan (this study).