Torrenticola haliki, Pesic, Vladimir & Smit, Harry, 2010

Pesic, Vladimir & Smit, Harry, 2010, New records of water mites (Acari: Hydrachnidia) from Malaysia, with descriptions of three new species, Zootaxa 2354, pp. 19-34 : 22-26

Torrenticola haliki sp. nov.

( Fig. 4A–D , 5A–B )

Type material. Holotype: male dissected and slide mounted in Hoyer's fluid, Malaysia, unnamed creek crossing Road 55 to Kuala Kubu Bharu, 3° 40.511 N 101° 44.511 E, alt. 823 m, 8.ii.2009. Paratypes: 0/1/0 (mounted), same data as holotype; 0/1/0 (mounted), River Gumut at crossing with road 55, 3° 37.155 N 101° 44.558 E, 18.ii.2009; 0/1/0, stream crossing road 159, between Ringlet and Lata Iskender, 4° 21.410 N 101° 20.156 E, alt. 795 m, 22.ii.2009.

Diagnosis. Medial suture line of Cx-2+3 long (ratio Cx-1 medial L/Cx-2+3 medial L 1.2 in male, 1.7–2.3 in female); ventral seta of P-2 located on the anteroventral extension short; ventral projection of P-2 noseshaped.

Description. Male: Idiosoma (ventral view: Fig. 4B ) L 575, W 450; dorsal shield ( Fig. 4A ) L 478, W 369, L/W ratio 1.3; dorsal plate 450; frontal plate L 109, W 44, L/W ratio 2.5; shoulder plate L 138, W 53, L/W ratio 2.6; shoulder/frontal plate L ratio 1.27; gnathosomal bay L 133, Cx-1 total L 228, Cx-1 medial L 94, Cx- 2+3 medial 80; ratio Cx-1 L/Cx-2+3 medial L 2.4; Cx-1 medial L/Cx-2+3 medial L 1.2; genital field L/W 125/103, L/W ratio 1.2, ejaculatory complex L 178; distance genital field–excretory pore 97, genital field– caudal idiosoma margin 133; capitulum ventral ( Fig. 4C ) L 270; chelicera L 324; palp ( Fig. 5A ) total L 301, dL and %L (in parentheses): P-1, 32 (10.6); P-2, 98 (32.6); P-3, 51 (16.9); P-4, 102 (33.9); P-5, 18 (6.0); L P- 2/P-4 ratio, 0.96; ventral seta of P-2 located on the anteroventral extension short; ventral projection of P-2 nose-shaped.

Female (from Kuala Kubu Bharu, in parentheses specimen from River Gumut): Idiosoma (ventral view: Fig. 4D ) L 678 (663), W 541 (509); dorsal shield L 566 (550), W 425 (419), L/W ratio 1.3 (1.3); dorsal plate 538 (513); frontal plate L 123 (119), W 48 (47), L/W ratio 2.6 (2.5); shoulder plate L 153 (163), W 53 (53), L/ W ratio 2.9 (3.1); shoulder/frontal plate L ratio 1.24–1.37; gnathosomal bay L 153 (153), Cx-1 total L 272 (253), Cx-1 medial L 119 (97), Cx-2+3 medial 53 (58); ratio Cx-1 L/Cx-2+3 medial L 5.1 (4.4); Cx-1 medial L/Cx-2+3 medial L 2.3 (1.7); genital field L/W 138 (141)/132 (128), L/W ratio 1.05 (1.1); egg maximum diameter L (158); distance genital field–excretory pore 163 (136), genital field–caudal idiosoma margin 216 (206); capitulum ventral L 323 (313); chelicera L 381 (361); palp ( Fig. 5B ) total L 358 (334), dL: P-1, 37 (35); P-2, 122 (112); P-3, 62 (55); P-4, 117 (113); P-5, 20 (19); %L: P-1, 10.3 (10.5); P-2, 34.0 (33.5); P-3, 17.3 (16.5); P-4, 32.7 (33.8); P-5, 5.6 (5.7); L P-2/P-4 ratio, 1.04 (0.99); shape and setation as in male.

Etymology. Named after Dr L. Halík in appreciation of his studies of Malaysian water mites.

Remarks. Halík (1930) described Torrenticola semisuta based on two male specimens from the S. Batung Padang, Cameron Highlands, Perak, Malaysia. Later, Wiles (1991) described the female based on specimens from Sungai Gombak, Selangor, Malaysia. He noted that the seta of P-2 on the ventral extension is much reduced in the specimens from Gombak but otherwise agreed with Halk’s description. During our study in the wide area of the locus typicus of T. semisuta , we collected two forms which were provisionally assigned to T. semisuta in the concept of a very variable species as proposed by Wiles (1997) and later followed by Pesic & Smit (2009a). Most populations of our study agree well with the description given by Wiles for Malaysian material of T. semisuta (see: Wiles 1991, 1997). On the other hand, specimens from the Jerian stream fit perfectly the original description of T. semisuta given by Halík (1930) (and differ from Malaysian specimens attributed by Wiles to T. semisuta ) in the presence of longer ventral seta on P-2, a less distally protruding and much slender P-2 ventral projection (compare Figures 3D–E and 5A–B ). Further differences regarding the shorter medial suture line of Cx-2+3, the shortened postgenital area and Cx-4 less extended posterior to the genital flaps in the both sexes of T. semisuta from the Jerian stream were noted. As no specimens with intermediate character combinations are found in the wide area of the locus typicus of T. semisuta , it is obvious that these Malaysian populations (assigned by Wiles to T. semisuta ) differ from the original description of T. semisuta and represent a separate taxon, Torrenticola haliki sp. nov.

Distribution. Malaysia.

Figures

FIGURE 4 A – D. Torrenticola haliki sp. nov. (A – C = male; D = female): A = dorsal shield; B, D = ventral shield; C = capitulum and chelicera. Scale Bars = 100 μm.

FIGURE 5 A – B. Torrenticola haliki sp. nov. (A = male; B = female): palp, medial view. Scale Bar = 100 μm.

FIGURE 3 A – E. Torrenticola semisuta (Halík, 1930), (A – B, D – E = male; C = female): A = dorsal shield; B – C = ventral shield; D = palp, lateral view; E = palp, medial view. Scale Bars = 100 μm.