Torrenticola (Torrenticola) arabica, Smit & Pesic, 2010

Smit, H. & Pesic, V., 2010, New Species Of Water Mites From Oman, With Some Zoogeographical Notes (Acari: Hydrachnidia), Acarologia 50 (2), pp. 151-195 : 157-161

Torrenticola (Torrenticola) arabica n. sp.

( Figures 4 A-G, 5A-B)

Type series — Holotype: male, stream Wadi Ghul , Oman, 23°10.297 N 57°11.996 E, alt. 805 m, 12-xi-2008 . Paratypes: 20/26/0 (0/1/0 mounted), same data as holotype.

Further records — 9/12/0 (2/1/0 mounted), stream Wadi Ban Auf, Oman, 23°16.699 N 57°27.690 E, alt. 655 m, 13-ix-2008 .

Diagnosis — Median suture line of Cx-II+III short; Cx-IV extended posterior to genital field in both sexes; genital field L/W ratio 1.05-1.13 in male; P-2 ventral projection curved distally; capitulum with a long rostrum; postgenital area in the male well developed, ratio postgenital L/idiosoma L 28.8-29.0.

Description

Male — (holotype, in parentheses measurements of specimens from Wadi Ban Auf, n=2). Idiosoma (ventral view: Fig. 4B ) L 759 (694-747), W 588 (556- 637); dorsal shield ( Fig. 4A ) L 634 (606-675), W 456 (425-475), L/W ratio 1.39 (1.42-1.43); dorsal plate 606 (581-644); shoulder plate L 194 (184-201), W 63 (59-66), L/W ratio 3.1 (3.1); frontal plate L 133 (131- 136), W 53 (44-50), L/W ratio 2.5 (2.7-3.0); shoul- der/frontal plate L ratio 1.46 (1.4-1.5); gnathosomal bay L 167 (135-159), Cx-I total L 314 (256-291), Cx-I medial L 147 (119-128), Cx-II+III medial 86 (86-92); ratio Cx-I L/Cx-II+III medial L 3.65 (2.8-3.4); Cx- I medial L/Cx-II+III medial L 1.7 (1.3-1.5); genital field L/W 141 (139-144)/133 (127-128), L/W ratio 1.05 (1.1-1.13), ejaculatory complex ( Fig. 4G ) L 197 (184-197); distance genital field-excretory pore 186 (153-166), genital field-caudal idiosoma margin 219 (200-216); capitulum ( Fig. 4F ) ventral L 325 (306- 317); palp ( Figs. 4 C-E) total L 346 (332-343), L: P-1, 32 (31-32); P-2, 123 (112-122); P-3, 63 (62-63); P-4, 108 (105-106); P-5, 20 (20-22); %L: P-1, 9.2 (9.3); P-2, 35.6 (33.8-35.6); P-3, 18.2 (18.4-18.7); P-4, 31.2 (30.9-31.6); P-5, 5.8 (5.8-6.6); L P-2/P-4 ratio 1.14 (1.07-1.15); P-2 ventral projection curved distally.

Female — (paratype, in parentheses measurements of specimen from Wadi Ban Auf) similar to the male. Ventral shield ( Fig. 5B ) L 856 (813), W 669 (675); dorsal shield ( Fig. 5A ) L 772 (719), W 525 (522), L/W ratio 1.47 (1.38); dorsal plate 734 (688); shoulder plate L 216 (222), W 75 (73), L/W ratio 2.9 (3.0); frontal plate L 166 (153), W 63 (56), L/W ratio 2.6 (2.7); shoulder/frontal plate L ratio 1.3 (1.45); gnathosomal bay L 184 (169), Cx-I total L 328 (293), Cx-I medial L 142 (125), Cx-II+III medial L 44 (56); ratio Cx-I L/Cx-II+III medial L 7.5 (5.2); Cx-I medial L/Cx-II+III medial L 3.2 (2.2); genital field L/W 164 (159)/159 (163), L/W ratio 1.03 (0.98); distance genital field-excretory pore 247 (230), genital fieldcaudal idiosoma margin 316 (292); capitulum ventral L 363 (364); palp total L 384 (391), L: P-1, 35 (34); P-2, 132 (139); P-3, 71 (71); P-4, 123 (122); P- 5, 23 (25); %L: P-1, 9.1 (8.7); P-2, 34.4 (35.6); P-3 18.5, (18.2); P-4, 32.0 (31.2); P-5, 6.0 (6.4); L P-2/P-4 ratio 1.07 (1.14); shape and setation as in male.

Remarks — Due to a ventral projection on P- 2 which curves distally, one (of 4) P-4 ventral setae long, capitulum with a long rostrum, similarly shaped ejaculatory complex and Cx-IV posteriorly extended well beyond genital field in both sexes, Torrenticola arabica n. sp., closely resembles T. semisuta (Halík, 1930), a species widespread from the Indian Himalayas to Malaysia ( Wiles, 1997b; Pe˘si´c et al., 2007; Pe˘si´c and Smit, 2009). Torrenticola semisuta (for an analysis of diagnostic characters of this species see Pe˘si´c and Smit, 2009) can be distinguished from T. arabica n. sp., in the following features: Cxgl-4 located sub-apically (apically in T. arabica n. sp.), male genital field more elongated (L/W 1.23-1.25; 1.05-1.13 in T. arabica n. sp.), the excretory pore and Vgl-2 slightly shifted from the line of primary sclerotization in both sexes, and the shortened male postgenital area (18.8-22% of the total idiosoma L; in T. arabica n. sp. 28-29%).

Etymology — The species is named for its occurrence in Arabian Peninsula.

Distribution — Oman.

Figures

FIGURE 4: Torrenticola arabica n. sp., male (A-D, F holotype; E, G specimen from Wadi Ban Auy): (A) – dorsal shield; (B) – idiosoma, ventral view; (C) – palp, medial view; (D-E) – palp, lateral view; (F) – capitulum; (G) – ejaculatory complex. Scale bars = 100 µm.

FIGURE 5: Torrenticola arabica n. sp., female: (A) – dorsal shield; (B) – idiosoma, ventral view. Scale bars = 100 µm.