Atractides longisetus Pesic, 2002

Pesic, Vladimir M., 2003, New records of the water mite genera Atractides Koch and Sperchon Kramer from the Balkan, with the description of one new species, Zootaxa 168, pp. 1-12 : 7-10

Atractides longisetus Pesic, 2002

( Figs.12­14 )

Material examined: Serbia and Crna Gora: Crna Gora: CG58 Komovi Mt., a little stream (tributary of the Supacki stream) near village Opasanica, 0 9.09.2001, leg. Pesic (0/3/0); ibid., 20.09.2002, leg. Pesic (1/2/0); CG1 Niksic, Vilina Cave near village Vidrovan, 660 m asl., 17.09.1999, leg. Pesic (1/0/0); CG55 Mojkovac, a little stream near village Proscenje, 31.08.2001, leg. Pesic (1/0/0).

Description

Female (measurements of female from Vilina Cave are given in parentheses): Length of idiosoma 643, width 486. Dorsally the integument is lineated (but lines arranged more densely and rather short as in Fig. 13 ) View of coxal and genital field: see Fig. 12 . Length between anterior end of first coxae and posterior end of fourth coxae 388 (371); Cx­3 width 458 (461), Cx­1+2 width 385 (403); Cx­1+2 medial suture 110 (107) in length; distance from lateralmost tips of Cx­2 to the medioposterior edge of Cx­1+2 285 (297); medioposterior edge of Cx­3+4 with extended posterior margin of secondary sclerotization. Measurements of mouthparts: palp total length 397.3 (382.7), dorsal lengths of PI­ PV: P­1 38.5 (36.5), P­2 86.5 (82.7), P­3 106 (103.9), P­4 130 (123.1), P­5 36.5 (36.5); relative lengths [% total length] (in parentheses): P­1 9.7 (9.5), P­2 21.8 (21.6), P­3 26.6 (27.1), P­4 32.7 (32.2), P­5 9.2 (9.5); length ratio P­2/P­4 is 0.66 (0.67); palp ( Fig. 14 ): more slender than in males, P­2 with a ventrodistal hump. Genital field: 157 (145) in length, 161.5 (148) in width; gonopore 111.5 (106) in length; Ac in triangular position, Ac­1­3 length 51 (48)–58 (50)–54 (52); anus smooth; Vgl­1 separate from Vgl­2.

I­L ( Fig. 15 ): S­1/2 far distanced and heteromorph, S­1 slender, S­2 enlarged in the basal third; I­L­6 curved, distally strongly narrowed; I­L­5 dorsal length 254 (244), I­L­5 ventral length 162.5 (142), ratio dorsal length I­L­5 /ventral length 1.56 (1.72), I­L­5 central height 67.3 (68), ratio dorsal length I­L­5/central height 3.77 (3.59), S­1 length 131 (140.4), ratio length S­1/ width 13.6 (14.6), S­2 length 98 (100), ratio length S­2/width 5.6 (5.2), distance of sword setae at I­L­5 42 (42); length ratio S­1/2 1.34 (1.4); I­L­6 length 192 (192), I­L­6 central height 17 (15.5), ratio length I­L­6/central height 11 (12.4); length ratio I­L­5/6 1.32 (1.27).

Remarks: Due to the character combination of lineated dorsal integument, smooth anus, Vgl­1/2 not fused, and ventral margin of P­2 slightly protruding also in females, and arrangement of the female Ac in a triangular line, A. longisetus Pesic, 2002 , is similar to A. panniculatus ( Viets, 1925) , A. remotus Szalay, 1953 , and A. fissus ( Walter, 1927) . From all this species, the male of A.longisetus can be distinguished on the basis of a remarkably longer ventral hairs on P­4 (L= 137 in holotype, 155 in specimens from Proscenje) ( Pesic, 2002). There is no difference in the I­L­5/6 ratio between females of the aforementioned species. Atractides longisetus females are more similar to A. remotus in a more slender I­ L­6 (L/HB ratio 9.0­9.9). Female of A. longisetus , can be distinguished from A. remotus on the basis of a shorter median suture Cx­1 (mL= 156 in A. remotus [from Gerecke (in press)]), shape of medioposterior edge of Cx­3+4 (in A. remotus margin without secondary sclerotization, and shape of integument (finely lineated in A. remotus ). Most dimensions and proportions of the male from Komovi agree with the holotype. Differences are found in a larger genital field (L/W 131/144; in type series L/W <115/130), and a longer I­L­5 (L I­L­5 192; in holotype L I­L­5 179). In view of the good agreement in proportions these differences are most probably age­depending.

Biology: As indicated by the few so far known records, A. longisetus is a rhitrobiontic species, which inhabits preferably streams at middle elevations.

Distribution: Serbia and Crna Gora.

Figures

FIGURES 12 ­ 15. Atractides longisetus Pesic, 2002, female: 12 = coxal and genital shield; 13 = integument, dorsal (at anterior margin); 14 = palp; 15 = I­L­ 5 / 6. Scale bars = 0.1 mm.