Hydrachna conjecta Koenike, 1895

Davids, Kees, Sabatino, Antonio Di, Gerecke, Reinhard, Gledhill, Terence & Smit, Harry, 2005, On the taxonomy of water mites (Acari: Hydrachnidia) described from the Palaearctic, part 1: Hydrachnidae, Limnocharidae and Eylaidae, Zootaxa 1061, pp. 36-64 : 39

Hydrachna conjecta Koenike, 1895

Material examined: " Hydrachna distincta " NHUB female "Ostfriesland, Sandwater bei Simoniswalde, 22.7.1910 Leege" (err., non H. distincta Koenike ); NHML female "Lincolnshire, Dr. C.F. George Coll. [slide] 1926­VI­24. 160 Balsam: 1898" (err., non H. distincta Koenike ).

Discussion: The specimen from the collection of Koenike is desiccated and mounted with the gnathosoma in situ, but there is sufficient evidence that it agrees well with H. conjecta . An area posterior to the genital field bears very distinct papillae that could have been confused with acetabula, suggesting the presence of an elongated genital field as is characteristic for H. distincta . The Lincolnshire specimen is mounted with the gnathosoma in situ. Probably it was attributed to H. distincta due to the equally rounded medial margin of the frontal sclerites, a character which is found to be variable when larger numbers of H. conjecta are studied. In view of the enlarged genital field, the attribution of both specimens to H. distincta is surely erroneous, they belong to H. conjecta (see below).