Taiwanicus, Pesic, Vladimir, Semenchenko, Ksenia A., Chatterjee, Tapas, Yam, Rita S. W. & Chan, Benny K. K., 2011

Pesic, Vladimir, Semenchenko, Ksenia A., Chatterjee, Tapas, Yam, Rita S. W. & Chan, Benny K. K., 2011, New records of water mites of the family Torrenticolidae (Acari, Hydrachnidia) with descriptions of two new species from Nanshih River system in Taiwan and redescription of Torrenticola ussuriensis (Sokolow, 1940) from the Russian Far East, ZooKeys 116, pp. 1-14 : 2-4

Torrenticola taiwanicus sp. n. Figs 234 C–D 7A

Type material.

Holotype male (NMNS-6599-001), dissected and slide mounted, Taiwan, Tonghou River, 24°50'23.74"N, 121°38'10.06"E, 25.viii.2009. Paratypes (NMNS-6599-002): 0/2/0 (0/1/0 mounted), Nanshih River, 24°54'09.87"N, 121°33'20.74"E, 02.iii.2010; 0/1/0, ibid., 25.viii. 2009; 1/0/0, Xindian River, 24°56'52.27"N, 121°32'42.54"E, 24.vi.2009; 1/2/0 (1/0/0 mounted), ibid., 16.vii.2009.

Diagnosis.

Shoulder plates fused with dorsal plate, the angles of the traces of shoulder plates posterior to setae Dgl-3 weakly pronounced, the angle of dorsal plate between frontal plates slightly pointed, the anterior part of the dorsal plate lying between the traces of the shoulder plates delimitation relatively wide; Cxgl-4 posterior to Cxgl-2, glandular pore Cxgl-4 distanced from Cxgl-2 by 81-90 µm; P-3 distal margin with denticles; P-4 stocky, relatively short (L P-2/P-4 ratio 1.1-1.2), without ventral denticles.

Description.

Male (holotype, in parentheses measurements of paratype). Idiosoma (ventral view: Fig. 2B, 7A) L 741 (734), W 587 (559); dorsal shield (Fig. 2A) L 658 (650), W 488 (494), L/W ratio 1.35 (1.32); dorsal plate L 631 (626); dorsal plate with colour pattern as illustrated in Fig. 4C; frontal plate L 150 (147), W 50 (50-52), L/W ratio 3.0 (2.8-3.0) gnathosomal bay L 139 (131), Cx-1 total L 281 (270), Cx-1 medial L 142 (139), Cx-2+3 medial 85 (91); ratio Cx-1 L/Cx-2+3 medial L 3.3 (3.0); Cx-1 medial L/Cx-2+3 medial L 1.67 (1.53); Cxgl-4 posterior to Cxgl-2, distance between glandular openings of Cxgl-4 and Cxgl-2 81-86 (81-86); genital field L/W 152 (156)/125 (122), L/W ratio 1.22 (1.28), ejaculatory complex conventional in shape, L 234; distance genital field–excretory pore 156 (150), genital field–caudal idiosoma margin 219 (216); capitulum ventral L 322 (328); chelicera total L 378 (383); palp (Figs 2 C–D) total L 302 (312), L: P-1 37 (39), P-2 102 (103), P-3 57 (60), P-4 89 (92), P-5 17 (18); P-2/P-4 ratio 1.15 (1.11); distal margin of P-3 with denticles; P-4 with four well developed ventral tubercles.

Female: Idiosoma (ventral view: Fig. 3A) L 828, W 663; dorsal shield L 756, W 541, L/W ratio 1.4; dorsal plate L 724; frontal plate L 156, W 52-55, L/W ratio 2.8-3.0; gnathosomal bay L 159, Cx-1 total L 300, Cx-1 medial L 141, Cx-2+3 medial 48; ratio Cx-1 L/Cx-2+3 medial L 6.25; Cx-1 medial L/Cx-2+3 medial L 2.9; distance between glandular openings of Cxgl-4 and Cxgl-2 86-90; genital field L/W 170/155, L/W ratio 1.1; distance genital field–excretory pore 181, genital field–caudal idiosoma margin 300; capitulum ventral (Fig. 3C) L 363; palp (Fig. 3B) total L 348, L: P-1 47, P-2 115, P-3 65, P-4 98, P-5 18; P-2/P-4 ratio 1.17; shape and setation as in male.

Etymology.

The species is named after the country where it was collected.

Remarks.

Due to the Cxgl-4 posterior to Cxgl-2 and the shape of palp (distal margin of P-3 with denticles, P-4 stocky and relatively shorter, without ventral denticles), the new species closely resembles Torrenticola ussuriensis (Sokolow, 1940) (see below). The latter species differs from Torrenticola taiwanicus sp. n., in the shape of dorsal shield (compare Figs 4 A–B with Figs 4 C–D) with the angle of dorsal plate between the frontal plates more pointed, the anterior part of the dorsal plate lying between the traces of the shoulder plates delimitation more narrower and the angles of the traces of shoulder plates delimitation posterior to setae Dgl-3 more pronounced. A further difference is found in the glandular openings of Cxgl-4 and Cxgl-2 more distanced from each other in Torrenticola taiwanicus sp. n. (81-90 vs. 48-60 µm in Torrenticola ussuriensis ).

Torrenticola occulta Lundblad, 1971, a species known from a single juvenile male specimen from Java ( Lundblad 1971) resembles Torrenticola ussuriensis and Torrenticola taiwanicus sp. n., due to the Cxgl-4 posterior to Cxgl-2 and P-4 without ventral denticles, but clearly differs in the shape of palp (see: Lundblad 1971, Fig. 12), with P-2 ventral margin straight and P-4 more slender and relatively longer, L P-2/P-4 ratio 1.0 vs. P-2 ventral margin concave, P-4 more stocky and distinctly shorter than P-2, L P-2/P-4 ratio 1.08-1.2 in Torrenticola ussuriensis and Torrenticola taiwanicus sp. n. Because some important characters (e.g., the shape and colour of dorsal plate, presence of denticles on distal margin of P-3, distance between the glandular openings of Cxgl-4 and Cxgl-2) were lacking in original description of Torrenticola occulta , additional specimens are required to clarify status of this species (see: Wiles 1997 and Pešić and Smit 2009, for an discussion on the Asian Torrenticola species that have a dorsal shield with shoulder platelets fused or partially fused with dorsal plate).

Distribution.

Taiwan.