Hydryphantes

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 : 13

Hydryphantes (s.str.) frici Thon, 1899

Species incerta

Discussion: This species was introduced mainly due to the reduced size and relatively small dimensions of the acetabula in a single male specimen on which the original description was based. The latter character is not suitable for species discrimination in Hydryphantes . Specimens which have single acetabula reduced in size - asymmetrically only on one side, both acetabula of one pair, or also more occasionally all three pairs - are regularly found in all better-documented species. Also with regard to idiosoma size, remarkable exceptions may be observed regularly in many species, and a difference in size of 1170 versus 1320 µm (following Thon in males of H. dispar to which H. frici is similar) is really negligible. As important details are not given in the original description and the holotype of H. frici is lost, a redescription and interpretation of its characteristics is impossible. As proposed by Gledhill & K.O. Viets (1976), it must be regarded as a species incerta .