Atractides pachydermis (Halbert, 1944)

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 : 339

ATRACTIDES PACHYDERMIS ( HALBERT, 1944)

Megapus pachydermis Halbert, 1944

Syn. to Atractides lacustris Lundblad, 1925 : syn. nov.

Type series: Holotype ♀ MNHD (1) Megapus pachydermis n. sp. TYPE L. Derg VI.21. J.N. H. [idiosoma, Glycerine Jelly, January 82 T. Gledhill]; (2) Megapus pachydermis n. sp. Palps ♀ River Shannon F.W.N. [Glycerine Jelly, January 82 T. Gledhill]. State of conservation: both slides remounted by Gledhill (1986b) after heavy damage. The problem of the different slide labels remains unsolved; at least the two sites of the mouthparts and idiosoma belong to the same catchment.

Discussion: Halbert used for the diagnosis of this species age-dependent characters such as thickness of integument and relative extension of idiosomal sclerites. He compared it with A. moniezi and A. pavesii only. Instead, all measurements and important morphological details are in good agreement with A. lacustris : I-L-5 with wide setal interspace, Vgl-1 + 2 fused, chelicera with relatively small claw (basal segment/ claw 2.76), palp rather slender (e.g. P-4 L/H 3.94), P-4 with an enlarged sword seta, P-5 without ‘cheeks’. A. pachydermis is probably a synonym of A. lacustris . However, in view of the bad state of the specimen, this record of A. lacustris from Ireland needs confirmation from future collections.

ATRACTIDES MAGNIROSTRIS ( MOTAŞ & TANASACHI, 1948)

Megapus (Rhynchomegapus) magnirostris Motaş & Tanasachi, 1948

Species dubia

Type series: Missing. Loci typici: Romania, Vallée du Sadul ( Dép. de Sibiu), affluent droit du Cibin (bassin de l’Olt), le 7/X/1948 […], 1 ♀ ; Vallée de la Bughea à Câmpu-Lung (dép. de Muscel), affl. du Râul-Târgului ( Bassin de l’Arges ), le 21/IV/1948, 1 ♂, 1 ♀ , le 27/X/1948, 2 ♀, le 25/X/1948, 1 ♂, 1 ♀

Discussion: The only diagnostic difference mentioned in the nonillustrated preliminary description concerned the palp (stronger than in A. moniezi ). In the more detailed redescription ( Motaş et al., 1958), no mention is made at all of differences to other species of the subgenus. A. magnirostris differs from A. pavesii and A. longirostris in the narrow setal interspace, and from A. lacustris and A. moniezi in the rather strong cheliceral claw (basal segment/claw 2.1). These characters, as well as some additional features (Vgl-1/2 not fused, P-5 bearing ‘cheeks’, sword seta on P-4 only slightly thickened) are similarly found in A. acutirostris . An important character of that species is S-1 and -2 placed side by side, while they are illustrated as staggered in figure 4 of Motaş et al. (1958). However, the segment is obviously not in a horizontal position, and the effect could be reinforced by the authors’ drawing technique. The few measurement data available for A. magnirostris do not differ remarkably from the values given here for A. acutirostris , but there are none at all for the taxonomically important first legs. Under these conditions, A. magnirostris must be designated a species dubia, possibly a synonym to A. acutirostris .