Torrenticola turkestanica (Sokolow, 1926)

Pesic, Vladimir, Semenchenko, Ksenia A. & Lee, Wonchoel, 2013, Torrenticolid water mites from Korea and the Russian Far East, ZooKeys 299, pp. 21-48 : 35-39

Torrenticola turkestanica (Sokolow, 1926) Figs 10, 11 G–H

Atractides turkestanicus Sokolow, 1926: 74.

Material examined.

SOUTH KOREA: CR3 River Inje, 38°03.961'N, 128°10.516'E, 225 m asl., 8.x.2012 Pešić & Karanović 1/1/0 (mounted, NIBRIV0000268852).

Morphology.

General features. Idiosoma elongated (dorsal shield L/W ratio 1.5-1.6); dorsal shield with colour pattern as illustrated in Figs 11G-H; Cxgl-4 subapical; gnathosoma ventral margin strongly curved; P-2 ventral margin convex, P-2 and P-3 with a subrectangular, apically serrated ventrodistal projection, P-4 stocky with well developed ventral protuberance bearing one long and three short setae (Figs 10C-D). Male: Medial suture line of Cx-II+III moderately long; genital field subrectangular in shape, ejaculatory complex normal in shape; excretory pore and Vgl-2 located on the margin of primary sclerotization. Female: Posterior suture line of Cx-IV curved and well evident; genital field excretory pore and Vgl-2 away from the line of primary sclerotization.

Measurements. Male: Idiosoma (ventral view: Fig. 10A) L 700, W 441; dorsal shield (Figs 7B, 11G) L 575, W 375, L/W ratio 1.5; dorsal plate L 541; shoulder plate L 172-174, W 48-56, L/W ratio 3.1-3.6; frontal plate L 106-116, W 44-47, L/W ratio 2.4-2.5; gnathosomal bay L 133, Cx-I total L 270, Cx-I medial L 137, Cx-II+III medial 97; ratio Cx-I L/Cx-II+III medial L 2.8; Cx-I medial L/Cx-II+III medial L 1.4. Genital field L/W 156/122, ratio 1.28; distance genital field–excretory pore 137, genital field–caudal idiosoma margin 169; ejaculatory complex L 212. Gnathosoma vL 283; chelicera total L 323; palp total L 272, dL: P-1, 28; P-2, 88; P-3, 52; P-4, 84; P-5, 20; P-2/P-4 ratio 1.05.

Female. Idiosoma (ventral view: Fig. 10E) L 781, W 494; dorsal shield (Fig. 11H) L 650, W 409, L/W ratio 1.6; dorsal plate L 610; shoulder plate L 178-189, W 56-64, L/W ratio 3.0-3.2; frontal plate L 127-131, W 52-55, L/W ratio 2.3-2.5; gnathosomal bay L 145, Cx-I total L 297, Cx-I medial L 151, Cx-II+III medial 47; ratio Cx-I L/Cx-II+III medial L 6.3; Cx-I medial L/Cx-II+III medial L 3.2. Genital field L/W 169/151, ratio 1.12; distance genital field–excretory pore 188, genital field–caudal idiosoma margin 272. Gnathosoma vL 372; chelicera total L 316; palp total L 301, dL: P-1, 31; P-2, 99; P-3, 59; P-4, 92; P-5, 20; P-2/P-4 ratio 1.08.

Remarks.

The specimens examined from River Inje fit the description of Torrenticola turkestanica , a species described based on a single female from Tadjikistan (Sokolow 1926). The only difference with the original description is found in a broader genital field in the type specimen. Later on, populations provisionally assigned to Torrenticola turkestanica , mainly based on the approved non-identity with the alternative species, were reported from Indian Himalayas ( Pešić et al. 2007) and Thailand ( Pešić and Smit 2006). The populations from Thailand differ from our material and the original description in a less slender idiosoma (dorsal shield L/W ratio 1.3-1.4, data taken from Pešić and Smit 2006), a much shorter ventral seta on P-2 and more slender P-4, and very likely represent an new species. The additional material and finding of a male from the locus typicus is necessary to clarify the taxonomy of Torrenticola turkestanica (the holotype may be missing, not found in the Zoological Institute of St. Petersburg, Denis Tumanov pers. comm).

Torrenticola japonica Imamura, 1953, a species described based on a single female from a stream in Shinjô-mura in Japan ( Imamura 1953), resembles Torrenticola turkestanica in the characteristic shape of the palp (ventral margin of P-2 convex, P-2 and P-3 with subrectangular ventrodistal projection). From the latter species, Torrenticola japonica differs in a broader idiosoma, a dorsal shield with broader shoulder platelets and posterior suture line of Cx- IV not extending far beyond genital field (see: Imamura 1953). However as the holotype of Torrenticola japonica is probably lost (Hiroshi Kajihara, pers. comm), additional material and selection of a neotype from the locus typicus is necessary to clarify its taxonomy.

Imamura (1953) reported a single male of Torrenticola elliptica Maglio, 1909, from a stream in Shinjô-mura in Japan. However due to the presence of subrectangular ventrodistal projections on P-2 and P-3 and a convex ventral margin of P-2, his illustrations show a general conformity with Torrenticola japonica and Torrenticola turkestanica . It is very likely that the specimen attributed by Imamura (1953) to Torrenticola elliptica is conspecific with Torrenticola japonica , especially as both species were collected from the same location and on the same day.

Habitat.

A permanent sandy/bouldery river with considerable exposure to sunlight (Fig. 14E).

Distribution.

Tadjikistan (Sokolow 1926), Indian Himalayas ( Pešić et al. 2007), Thailand ( Pešić and Smit 2006, but see remarks above). New for the fauna of Korea.