Panisus torrenticolus Piersig, 1898

Sabatino, Antonio Di, Gerecke, Reinhard, Gledhill, Terence & Smit, Harry, 2009, On the taxonomy of water mites (Acari: Hydrachnidia) described from the Palaearctic, part 2: Hydryphantoidea and Lebertioidea, Zootaxa 2266, pp. 1-34 : 6

Panisus torrenticolus Piersig, 1898

Panisus clypeolatus (Maglio, 1909) , nov. syn.

Material examined: Germany, D 453, Baden-Württemberg, Goldersbach near Teufelsbrücke (TÜ), from a 12-month investigation 1996/97, (8/3/0).

Discussion: Panisus torrenticolus is characterized by a typical porosity of the muscle attachment sclerites, having a centre of fine pores surrounded by a circle of large pores and an outer area of finer pores - following K. Viets (1936) the porosity is "triplicate" because the outer fine pores are often larger than the inner fine pores. In particular the round dorsocentral plates, due to the presence of the ring of large pores have a spoke-wheel-like aspect. Plates Dc-3 - by Bader (1981) erroneously named "Dc-2" - may be found completely separate or fused to various degrees within members of a single population. The frontal shield is as long as wide, dorsolateral plates develop no, or only weakly projecting, lateral extensions.

The original description of Panisus clypeolatus does not include original details that allow a definition of this taxon, and the type material is lost. As mentioned above, the medial fusion of Dc-3, for a long time considered a diagnostic feature of this species ( Lundblad 1956, Bader 1981), is also found in P. torrenticolus of which P. clypeolatus consequently should be considered a junior synonym.

A still open question concerns the taxonomic state of P. lundbladi Bader, 1981 from Spain. In the enlarged frontal shield and presence of extensive lateral ramifications of dorsolateralia, this species is similar to P. michaeli , while it agrees with P. torrenticolus in the reduced dimensions and the presence of a (indistinct) ring of larger pores on most muscle attachment sclerites. The fusion of Dl-4 with Dc-5, considered a diagnostic feature of P. lundbladi by Bader, like fusions of other dorsolateralia, can be observed as an individual aberration in all species of the genus.