Torrenticola minuta ( Lundblad, 1941 )

Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Malaysian Borneo, Zootaxa 3840 (1), pp. 1-72 : 17

Torrenticola minuta ( Lundblad, 1941)

( Figs. 11A–D , 16A–B , 17A–B , Fig. 23E )

Atractides minutus Lundblad 1941: 99 .

New records. Malaysia, Borneo , stream Kemantis , Sayap , Mt Kinabalu , 6º09.841 N, 116º33.936 E, alt. 928 m asl., 16.ix.2012 Smit 2[one juvenile]1/0 (1/0/0 mounted); Mahua stream, Mahua, Crocker Range, 5º47.838 N, 116º24.510 E, alt. 1052 m asl., 21.ix.2012 Smit 2/0/0 (1/0/0 mounted); Kibamabangan River, Crocker Range, 5º51.28 N, 116º08.417 E, alt. 433 m asl., 18.ix.2012 Smit 2/1/0; Great Lumotok stream, Mt Kinabalu, 6º09.336 N, 116º08.417 E, alt. 433 m asl., 18.ix.2012 Smit 0/1/0 (mounted) .

Morphology

General features —Idiosoma roundish (dorsal shield L/W ratio 1.2); shoulder platelets fused to the large dorsal plate; dorsal shield with colour pattern as illustrated in Figs. 16A–B ; gnathosomal bay U-shaped; Cxgl–4 subapical, only slightly posterior of Cx-I tips; suture line of Cx-IV distinct, extending posteriorly beyond posterior margin of genital field; excretory and Vgl–2 pore away from the line of primary sclerotization, excretory pore on the level with Vgl–2; gnathosoma with curved ventral margin; P-2 longer than P-4, P-2 ventral margin slightly convex, P-2 ventrodistal protrusion, bluntly pointed, curved towards distal; P-3 ventrodistal protrusion bluntly pointed; P-4 with well developed ventral protuberances, ending in two tips separated by a concavity ( Figs. 11C–D ). Male: medial suture line of Cx-II+III short; genital field subrectangular in shape; ejaculatory complex conventional in shape ( Fig. 23E ). Female: genital field pentagonal in shape.

Measurements

Male (from stream Kemantis)—Idiosoma (ventral view: Figs. 11A , 17A ) L 628, W 459; dorsal shield ( Fig. 16A ) L 511, W 413, L/W ratio 1.24; dorsal plate L 481; frontal plate L 127–128, W 44, L/W ratio 2.9. Gnathosomal bay L 125, Cx-I total L 266, Cx-I mL 142, Cx-II+III mL 58; ratio Cx-I L/Cx-II+III mL 4.6; Cx-I mL/ Cx-II+III mL 2.5. Genital field L/W 119/100, ratio 1.19; ejaculatory complex L; distance genital field-excretory pore 114, genital field-caudal idiosoma margin 183. Gnathosoma vL 293; chelicera total L 339; palp total L 289–291, dL/H, dL/H ratio: P-1, 31/31, 1.0; P-2, 101-102/55, 1.86; P-3, 52/46, 1.13; P-4, 88-89/28, 3.2; P-5, 17/9, 1.85; P-2/P-4 ratio 1.15.

Female (from Great Lumotok stream)—Idiosoma (ventral view: Figs. 11B , 17B ) L 625, W 459; dorsal shield ( Fig. 16B ) L 497, W 412, L/W ratio 1.2; dorsal plate L 469; frontal plate L 128, W 41, L/W ratio 3.2. Gnathosomal bay L 130, Cx-I total L 266, Cx-I mL 136, Cx-II+III mL 37.5; ratio Cx-I L/Cx-II+III mL 7.1; Cx-I mL/Cx-II+III mL 3.6. Genital field L/W 129/114, ratio 1.13; distance genital field-excretory pore 113, genital field-caudal idiosoma margin 191. Gnathosoma vL 314; chelicera total L 358; palp total L 296–297, dL/H, dL/H ratio: P-1, 34/ 29, 1.16; P-2, 101-102/57, 1.78; P-3, 54/48, 1.13; P-4, 90/28, 3.25; P-5, 17/10, 1.7; P-2/P-4 ratio 1.13.

Remarks. Wiles (1999) reported T. minuta from several sites in the catchment area of the River Temburong in North Brunei. He mentioned that his specimens differ from those from Peninsular Malaysia in having Cxgl-4 more posteriorly located, near I-L insertion, instead of being subapical (located just posterior of Cx-I tips).

Distribution. Sulawesi ( Wiles 1997), Borneo ( Wiles 1999, our study).

Figures

FIGURE 11A–D. Torrenticola minuta (Lundblad, 1941) (A,C—male from Kemantis stream; B,D—female from Great Lumotok stream): A–B = idiosoma, ventral view; C–D = palp, medial view. Scale bars = 100 µm.

FIGURE 16A–F. Photographs of dorsal shield. A–B Torrenticola minuta (Lundblad, 1941): A = male, Kemantis stream; B = female, Great Lumotok stream. C–D T. neoindica n. sp., Mahua stream: C = male holotype; D = female paratype. E T. tjiwalensis (K. Viets, 1935), male, Mahua stream. F. T. schilthuizeni n. sp., female holotype, Kibamabangan River.

FIGURE 17A–F. Photographs of ventral shield. A–B Torrenticola minuta (Lundblad, 1941): A = male, Kemantis stream; B = female, Great Lumotok stream. C–D T. neoindica n. sp., Mahua stream: C = male holotype; D = female paratype. E T. tjiwalensis (K. Viets, 1935), male, Mahua stream. F T. schilthuizeni n. sp., female holotype, Kibamabangan River.

FIGURE 23A–H. Photographs of ejaculatory complex. A Torrenticola borneoensis n. sp. B T. kinabaluensis n. sp.. C T. longipalpis Wiles, 1997. D T. sabahensis n. sp. E Torrenticola minuta (Lundblad, 1941). F T. neoindica n. sp. G Neoatractides uniscutatus n. sp. H Pseudotorrenticola borneoensis n. sp.