Atractides gereckei Pesic

Pesic, Vladimir, Saboori, Alireza, Asadi, Mahdieh & Vafaei, Reza, 2004, Studies on water mites of the family Hygrobatidae (Acari, Hydrachnidia) from Iran, I. The water mite genus Atractides Koch, with the description of five new species, Zootaxa 495, pp. 1-40 : 17-20

Atractides gereckei Pesic sp. nov

( Figs. 26–33 )

Type material: Holotype: male, dissected and slide mounted in Hoyer's fluid; Iran: IR16 Kerman Province, stream in village Sirch, 50 km E from Kerman (30°12'37 N 57°34' 11E), 1834 m asl., 24.07.2003, leg. Pesic. Paratypes: 1 male, same data as holotype; IR25 Kerman Province, Vamegh Abad stream near Vamegh Abad village (30°3'39 N 57°17' 29E), 1930 m asl., 27.07.2003, leg. Pesic, 1 male.

Females probably belonging to this species (not included in the type material): 5 females, same station as holotype; 4 females, IR25 Kerman Province, Vamegh Abad stream near Vamegh Abad village 27.07.2003, leg. Pesic.

Diagnosis: Males. Dorsal integument: finely striated; muscle attachments: unsclerotized. I­L: I­L­5 with S­1/2 strongly heteromorphic and distanced, S­1 long, distally thickened, S­2 shortened, enlarged; I­L­6 very long and slender. Excretory pore: smooth; Vgl­1: not fused with Vgl­2. Palp: sexual dimorphism? ventral margin of P­4 with remarkable long ventral hairs, sword seta strong and curved, inserted halfway between ventral hairs.

Description

Male: Length of idiosoma 464, width 305. Dorsally the integument is finely striated; muscle attachments: unsclerotized. Coxal field: mediocaudal margin of Cx­1+2 indented between the laterally directed apodemes of Cx­2 ( Fig. 26 ); length between anterior end of first coxae and posterior end of fourth coxae 281; Cx­3 width 304, Cx­1+2 width 238.5; Cx­1+2 medial suture 86.5 in length; distance from lateralmost tips of Cx­2 to the medioposterior edge of Cx­1+2 184.6. Measurements of mouthparts: chelicera 176 in length, claw 52 in length; palp total length 265.5, dorsal length and relative length (% total length, in parentheses) of single segments: P­1 28 (10.5), P­2 61.5 (23.2), P­3 63 (23.7), P­4 82 (30.9), P­5 31 (11.7); length ratio P­2/P­4 is 0.75; palp ( Fig. 28­29 ): P­2 with ventral projection, ventral margin of P­4 with remarkably long ventral hairs, sword seta strong and curved, inserted halfway between ventral hairs. Genital field ( Fig. 30 ): with nearly straight, irregular anterior margin; 75 in length, 82.7 in width, Ac­1­3 length 18­22­23; excretory pore smooth; Vgl­1: separated from Vgl­2.

I­L ( Fig. 27 ): I­L­5 ventral margin slightly expanding near the insertion of the ventral seta, S­1/2 strongly heteromorphic and distanced, S­1 long, distally thickened, S­2 shortened, enlarged, with irregular blade and a blunt tip; I­L­6 long and slender, only slightly narrowed from the base to the tip; I­L­5 dorsal length 150, I­L­5 ventral length 91, ratio dorsal length I­L­5 /ventral length 1.65,I­L­5 central height 52, ratio dorsal length I­L­5/ central height, 2.9 S­1 length 87, ratio length S­1/width 11.3, S­2 length 65.4, ratio length S­2/ width 6.8, distance between sword setae of I­L­5 23; ratio length S­1/2 1.33; I­L­6 length 129, I­L­6 central height 17.3, ratio length I­L­6/central height 7.45; ratio length I­ L­5/6 1.16.

Female (from Sirch, in brackets female from Vamegh Abad stream): Length of idiosoma 707 (679), width 536 (507). Dorsally the integument is finely striated. Coxal field: length between anterior end of first coxae and posterior end of fourth coxae 362 (294); Cx­ 3 width 415 (373); Cx­1+2 medial suture line 110 (88.5) in length; distance from lateralmost tips of Cx­2 to the medioposterior edge of Cx­1+2 215 (211.5). Measurements of mouthparts: chelicera 235 in length, claw 65.4 in length; palp total length 347 (342), dorsal length of single segments: P­1 31 (33), P­2 81 (80), P­3 96 (94), P­4 104 (102.5), P­5 35 (33); relative length (% total length) of single segments: P­1 8.9 (9.6), P­2 23.3 (23.4), P­3 27.7 (27.5), P­4 30.0 (30.0), P­5 10.1 (9.6); ratio length P­2/P­4 is 0.78 (0.78); palp ( Fig. 32 ): P­4 ventral margin 2:2:1, with denticles near hair insertions, but the distal one only little projecting. Genital field ( Fig. 33 ): praegenital sclerite equally sickle­shaped, Ac in an equally curved line; 163 in length, 154 in width, Ac­1­3 length 31 (34.6)­34 (36.5)­33 (25); excretory pore smooth; Vgl­1: separated from Vgl­2.

I­L( Fig. 31 ) I­L­5 S­1/2 distanced; I­L­5 dorsal length 208 (207), I­L­5 ventral length 104 (104), ratio dorsal length I­L­5 /ventral length 2.0 (1.99), I­L­5 central height 73 (69), ratio dorsal length I­L­5/central height 2.9 (3.0), S­1 length 134.6 (126),ratio length S­1/ width 14.0 (13.1), S­2 length 90.4 (88.5), ratio length S­2/ width 6.7 (7.4), distance between sword setae of I­L­5 47 (44); ratio length S­1/2 1.49 (1.42); I­L­6 length 194 (190), I­L­6 central height 15.4 (19.2), ratio length I­L­6 /central height 12.6 (9.9); ratio length I­L­5/6 1.07 (1.09).

Discussion: Species close to Atractides gereckei sp. nov. with a similar morphology and proportions of I­L (I­L­5/6 <1.2, I­L­5 stout, with relatively short ventral margin, S­1 at the tip thickened), unsclerotized excretory pore, and unfused Vgl­1/2, are Atractides distans K.Viets, 1914 , A. gomerae Lundblad, 1962 , A. allgaier Gerecke, 2003 , A. gassowskii ( Sokolow, 1934) , A. gracilis ( Sokolow, 1934) , and A. odarkensis ( Sokolow, 1934) . From all these species, Atractides gereckei nov. sp. is easily distinguished in the male by the shape of palp with remarkabe long ventral hairs of the P­4.

Furthermore, from the latter three A. distans ­like species, described from Siberia, Atractides gereckei nov. sp. differs, in a shorter median suture line Cx­1+2 and more slen­ der segments I­L­5, from A. allgaier (in parentheses data from Gerecke 2003), in a densely striated, not lineated integument, a shorter and slender S­1 (S­1 L>130, L/W<13.0) and less heteromorphic setae S­1/2 (L ratio S­1/2 1.52­1.60 in female).

A. gomerae (in parentheses data from Gerecke 2003), so far known from a single female from Spain, differs from the specimens suspected to represent the females of A. gereckei sp. nov. in a smaller genital field (L/W <130/130µm) and acetabula (<25µm), and the sword seta P­4 located more proximally. As compared with A. gereckei sp. nov., females of A. distans can be distinguished by the more slender setae S­1/2 (L/W S­1> 15.0, S­2> 8.5).

From A. longisetus Pesic, 2002 (in brackets data from Pesic 2002), a similar species due to the remarkabe long ventral hairs of the male P­4, and the absence of denticulation or rugosity on the projection of the male P­2, A. gereckei sp. nov. is easily distinguished in a densely striated, not lineated integument, a genital field with Ac arranged in curved line (in triangular position, Ac­1 and Ac­3 approached to each other), and a smaller dimensions of genital acetabula (maximum diametar> 40 m).

Etymology: The species is named after Dr. Reinhard Gerecke (Tübingen) in appreciation of his studie of the genus Atractides and support to first author.

Biology: Atractides gereckei sp. nov. is a rhitrobiontic species, which inhabits streams at higher elevations

Distribution: Iran, only known from the Kerman Province.

Figures

FIGURES 26 – 30. Atractides gereckei sp. nov., male: 26 = coxal field; 27 = I­L­ 5 / 6; 28 – 29 = palp; 30 = genital field. Scale bars = 0.1 mm.

FIGURES 31 – 33. Atractides gereckei sp. nov., female: 31 = I­L­ 5 / 6; 32 = palp; 33 = genital field. Scale bar = 0.1 mm.