Atractides cf. lunipes Lundblad, 1956

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 : 11-12

Atractides cf. lunipes Lundblad, 1956

( Figs. 16­19 )

Material examined: Macedonia: MA135 Ohrid Lake, without known sampling date, 658 m asl., ex coll. Georgiev & Petkovski (0/8/0).

Description

Female (measurements based on 2 specimens): Length of idiosoma 907­914, width 736­743. Dorsally the integument is lineated; muscle attachments: unsclerotized. Length between anterior end of first coxae and posterior end of fourth coxae 427; Cx­3 width 579; Cx­1+2 width 358; Cx­1+2 medial suture 121­127 in length; distance from lateralmost tips of Cx­2 to the medioposterior edge of Cx­2+3 250; Cx­1+2 short and large, posterior margin Cx­1 medially straight, apodemes of Cx­ 2 in an acute angle; coxal plates with distinct medial and posterior margins with secondary sclerotization ( Fig. 16 ) Measurements of mouthparts: palp total length 363­365, dorsal lengths and relative lengths [% total length] (in parentheses) of PI­PV: P­1 34.6 (9.5), P­2 75 (20.6­20.7), P­3 100 (27.4­27.5), P­4 115 (31.6­31.8), P­5 38­40 (10.5­11); length ratio P­2/P­4 is 0.65; palp ( Fig. 17 ): P­2 ventral margin distally protruding and convex, P­3 ventrally straight, P­4 slender, ventral margin weakly extended near proximal hair insertion, sword seta halfway between ventral hairs. Genital field ( Fig. 19 ): 188.5­192 in length, 192­196 in width; praegenital sclerite compact, thick, genital plates curved; Ac­1­3 length 38.5­42/38.5­40/36­39; anus smooth; Vgl­ 1: fused with Vgl­2.

I­L ( Fig. 18 ): I­L­5 protruding between ventral seta and S­1 insertion, S­1/2 far distanced, heteromorphic; I­L­6 very slender and curved; I­L­5 dorsal length 234.6­238.5, I­ L­5 ventral length 140­144, ratio dorsal length I­L­5/ventral length 1.65­1.67, I­L­5 central height 57­59, ratio dorsal length I­L­5/central height 3.98­4.18, S­1 length 124­128, ratio length S­1/width 12.1­12.4, S­2 length 79.5­82, ratio length S­2/width 4.95­5.16, distance of sword setae at I­L­5 46­50; length ratio S­1/2 1.52­1.61; I­L­6 length 165­180, I­ L­6 central height 16.7­18.2, ratio length I­L­6 /central height 9.86­9.9; length ratio I­L­5/ 6 1.3­1.45.

Remarks: Atractides lunipes Lundblad, 1956 , is a well­defined species, but has not been recorded since the first description. According to Gerecke (in press) A. lunipes differs from all W palaearctic species in the very fine and slender seta S­1 (L/W ratio 20.4). A combination of further diagnostic characters is the lineated integument, a smooth anus, fused Vgl­1+2, setae S­1/2 far distanced, and I­L­6 very slender (L/HB ratio 12.06) (Gerecke, in press). The Macedonian specimens are in a general agreement with the holotype. However, there are numerous biometric differences (in parentheses the values of the holotype [from Gerecke (in press)]): S­1 length <130 (143), ratio length S­1/width 12.1­ 12.4 (20.4); S­2 length<85 (100); ratio length S­2/ width 4.9­5.2 (7.7); I­L­6 length 165­ 180 (193); ratio length I­L­6 /central height <10 (12.06); length ratio I­L­5/6 1.3­1.45 (1.17); genital field L/W>180 (L/W 162/166). The most noteworthy differences are the dimensions of I­L­6 and a less slender S­1. As the material at our comparasion from the French Pyrenees is scanty, the differences listed above do not allow for a taxonomic separation of the Macedonian populations. The stability of the discerning characters should be tested with more specimens from a wider geographic area. Furthermore, the attribution of the Macedonian populations to the species should be verified by studies on male specimens.

Biology: As indicated by females we found in the material, together with mite species characteristic for stagnant waters (Piona pusilla, P. rotundoides, Arrenurus sp.), A. cf. lunipes is probably a lenitophilous species.

Distribution: Presently, Atractides lunipes is known from the French Pyrenees and Macedonia, but its distribution is probably more extended. The only two findings in widely separate geographical regions is probably due its rareness as well as to our restricted knowledge of the genus Atractides Koch in large parts of Mediterranean region.

Figures

FIGURES 16 ­ 19. Atractides cf. lunipes Lundblad, 1956, female: 16 = coxal field; 17 = palp; 18 = I­L­ 5 / 6; 19 = genital field, excretory pore and Vgl. Scale bars = 0.1 mm.