Atractides (Atractides) arabicus, 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 : 170-173

Atractides (Atractides) arabicus n. sp.

( Figures 14 A-D, 15A-E)

Type material — Holotype: male, stream Wadi Ghul , Oman, 23°10.297 N 57°11.996 E, alt. 805 m, 12- xi-2008 . Paratypes: 12/5/0 (0/1/0 mounted), same data as holotype; 4/1/0 (0/1/0 mounted), small cascading stream Wadi Ghul , Oman, 23°09.702 N 57°12.151 E, alt. 805 m, 12-xi-2008 ; 1/0/0 (1/0/0 mounted), stream Hatta Pools , Oman, 24°41.165 N 56°09.556 E, alt. 421 m, 15-xi-2008 .

Diagnosis — Genital field in the male with anterior margin concavely indented and Ac-3 distanced from anterior two acetabula on each side, I-Leg-5 with S-1 and -2 far distanced (> 40 in both sexes), S-1 curved, with blunt tip, S-2 with strongly developed dorsal projection.

Description

General features — Dorsal integument: striated; muscle attachment plates smooth. Coxal field: mediocaudal margin of Cx-I+II with a large, slightly indented area between the laterally directed apodemes of Cx-II. Genital field: Ac in a weakly curved line. Palp: weak sexual dimorphism, P- 2 ventral margin slightly convex, P-3 straight, P- 4 sword seta near distal hair. I-Leg: I-Leg-5 with S-1 and -2 strongly heteromorphic and distanced, ventral seta close to insertion of S-1, curved, with blunt tip, S-2 with strongly developed dorsal projection, bluntly pointed, I-Leg-6 long and slender, only slightly narrowed from the base to the tip.

Male — (holotype, in parentheses measurements of specimen from stream Hatta Pools). Idiosoma L/W 553 (566)/366 (381). Coxal field ( Fig. 14B ): L 303 (316), Cx-III W 319 (325), Cx-I+II mL 71 (72), Cx-I+2 lL 169 (178). Palp ( Fig. 14D ): palp total L 302 (317), dL: P-1, 29 (30); P-2, 66 (71); P-3, 71 (77); P-4, 102 (105); P-5, 34 (34); %L: P-1, 9.6 (9.5); P- 2, 21.9 (23.1); P-3, 23.5 (24.3); P-4, 33.8 (33.1); P-5, 11.3 (10.7); L P-2/P-4 0.65 (0.68); P-4 ventral hairs long. Genital field ( Fig. 14C ): anterior margin concavely indented, lateral margin weakly indented between Ac-2 and Ac-3, L/W 89 (95)/94 (102), Ac-3 rather small, distanced from anterior two acetabula on each side, L Ac-1-3: 26 (26), 28 (28), 22 (25).

I-Leg ( Fig. 14A ): I-Leg-5 dL 212 (218), vL 114 (124), dL/Vl 1.86 (1.76), HB 50 (50), dL/HB 4.2 (4.4), S-1 L 100 (103), L/W 8.6 (8.9), S-2 L 63 (67), L/W 5.4 (7.3), distance of sword setae at I-Leg-5 43 (43), L S- 1/2 1.59 (1.54); I-Leg-6 L 159 (157), HB 15 (15), L/HB 10.3 (10.2); L I-Leg-5/6 1.34 (1.39).

Female — (from stream Wadi Ghul, in parentheses measurement of specimen from small cascading stream Wadi Ghul). Idiosoma L/W 944 (700)/663 (519). Coxal field ( Fig. 15D ): L 400 (378), Cx-III W 448 (389), Cx-I+II mL 78 (79), Cx-I+II lL 213 (204); apodemes Cx-II directed caudolaterally. Palp ( Fig. 15C ): palp total L 386 (373), dL: P-1, 34 (34); P-2, 85 (82); P-3, 102 (99); P-4, 128 (122); P-5, 37 (36); %L: P- 1, 8.8 (9.1); P-2, 22.0 (22.0); P-3, 26.4 (26.5); P-4, 33.2 (32.7); P-5, 9.6 (9.7); L P-2/P-4 0.66 (0.67). Genital field ( Fig. 15E ): L 163 (135), genital plates slightly indented between Ac, genital plate L 109 (100), L Ac-1-3: 35 (33), 34 (32), 35 (34).

I-Leg ( Fig. 15 A-B): I-Leg-5 dL 295 (294), vL 151 (154), dL/vL 2.0 (1.9), HB 76 (79), dL/HB 3.9 (3.7), S-1 L 119 (119), L/W 8.6 (7.4), S-2 L 74 (75), L/W 5.3 (5.4), distance of sword setae at I-Leg-5 77 (69), L S- 1/2 1.6 (1.6); I-Leg-6 L 209 (199), HB 18 (17), L/HB 11.8 (11.7); L I-Leg-5/6 1.4 (1.48).

Remarks — Atractides arabicus n. sp. is unique within the genus due to the particular shape of S-2 (with a well developed dent on the outer margin of seta). In addition, the male is characterized by the anterior margin of genital field concavely indented, with rather small Ac-3 distanced from the two anterior acetabula on each side.

Etymology — The species is named for its occurrence on the Arabian peninsula.

Distribution — Oman.

Figures

FIGURE 14: Atractides arabicus n. sp., male (A-B, D holotype, C paratype): (A) – I-Leg- 5 and - 6; (B) – idiosoma, ventral view; (C) – genital field; (D) – palp, medial view. Scale bars = 100 µm.

FIGURE 15: Atractides arabicus n. sp., female: (A-B) – I-Leg- 5 and - 6; (C) – palp, lateral view; (D) – coxal field; (E) – genital field. Scale bars = 100 µm.