Atractides

Gerecke, Reinhard, 2003, Water mites of the genus Atractides Koch, 1837 (Acari: Parasitengona: Hygrobatidae) in the western Palaearctic region: a revision, Zoological Journal of the Linnean Society 138, pp. 141-378 : 277-278

WESTERN PALAEARCTIC ATRACTIDES 277

stout I-L-5 and -6 with heteromorphic S-1 and -2, and S-1 curved, the gnathosoma with projecting rostrum, the chelicera with long, fine, and weakly curved claw, and the robust palp with strong sword seta on P-4. Males agree also in the P-4 with bluntly protruding ventral margin and ventral setae arranged close together. Apart from the name-giving Ac number, A. octoporus differs in the muscle attachments (without sclerotization, thus no dorsal shields in males) in the less strongly expressed heteromorphy of S-1 and -2, more slender I-L-6, and the short ventrodistal protrusion of the male P-2. The relatively short and thick S-1 and -2, extended secondary sclerotization of male Cx-4, gnathosoma with pointed rostrum, chelicera with long, needle-like claw, and long ventral hairs of P-4 characterize A. digitatus as a representative of the subasper species group. Also in A. subasper , the male dorsum has an extended sclerotization, in some populations with two unpaired dorsal shields as in A. digitatus .

Habitat: Rhithrobiont.

Distribution: Spain: known so far from three sites in Granada and Oviedo ( Lundblad, 1956); a new record from Aragon is provided here (1).

ATRACTIDES CLAVIPES LUNDBLAD, 1954

( FIG. 62A–H)

Type series: Holotype ♀ SMNH 4500 . Typ.; Atractides clavipes Ldbl. ♀ Portugal. Cintra. Monserrate-Park. Rännil [in Lundblad (1956): äusserst kleiner Bach im Alsophila-Walde ] 29.6.1935 Leg. O. Lundblad; additional record in the first description: France Vogesen. Schnellfliessender, nicht kalter Bach (Mosel) gleich südlich von Remiremont. 22.6.1953, 1 ♀.

Material examined: Spain, E 132, Aragon, Beceite, Rio Mataranya. Rheohelokrene Acampamento El Parrissal , 650 m, 18.04.1998 Gerecke 1 ♂, 5 ♀ .

Description:

General features dorsal integument: finely striated; muscle attachments: sexual dimorphism coxal field: Cx-1 + 2 mediocaudally narrowed and with tongue shaped medial tip, apodemes of Cx-2 directed laterally, Cx-4 with sexual dimorphism

I-L: slightly modified, I-L-5 short, with setae S-1 and -2 inserted on the same level and homoiomorphic, with blunt tip; I-L-6 weakly curved, strongly thickened from the base to the claw furrow, claw strong excretory pore: smooth; Vgl-1: not fused to Vgl-2 (except for mature males)

palp: P-2 without a ventrodistal protrusion, but forming a distinct ventrodistal angle, P-3 slightly concave proximally, slightly convex distally, P-4 with sexual dimorphism

Males

First description; specimen from E 132 Muscle attachments: Dgl-1 enlarged, medially nearly in touch; Postoc as an unsclerotized, granulated area of integument, D-1 and Dgl-3 fused to an irregular platelet, D-2–4 sclerotized as roundish platelets, D-5 as an unsclerotized area of integument, V-1–3 sclerotized, a small, unpaired medial sclerite anteriorly from genital field coxae: Cx-4 with broad border of secondary sclerotization including Vgl-3 genital field: round, with extended, convex anterior border of secondary sclerotization, posterior indentation bipartite due to a small mediocaudal projection; genital setae: 38