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.) dispar (Schaub, 1888)

Hydryphantes intermedius Daday, 1901 , nov. syn. Hydryphantes algeriensis Walter, 1925 , nov. syn.

Material examined: Hydryphantes algeriensis holotype 3 "leg. Gauthier, Algérie Agoulmine Boual-Sous, 22.2.1925 ", Algeria; two deutonymphs labelled as " Typus " of H. algeriensis in NHMB later attributed to H. placationis (Walter 1928) .

Discussion: Sokolow (1940) treated H. intermedius as a species incerta – with good reasons in view of the rather sketchy figures given in the original description. However, the shape of the frontal shield (probably illustrated in an oblique position by Daday) is considered nowadays to be of minor importance, and other information available from the original description (frontal shield with long posterior extensions, high swimming hair numbers on legs, stout shape of palp) are in perfect agreement with H. dispar , a species obviously unknown to Daday. So, notwithstanding the loss of type material, we consider H. intermedius a junior synonym of H. dispar .

In the description of H. algeriensis, Walter (1925) considered particularities in shape of the frontal shield and leg setation as diagnostic for H. algeriensis . He considered the species as intermediate between H. dispar and H. bucculentus Koenike, 1915 , synonymized with H. dispar by K. Viets (1956). In the holotype, the following details and measurements were observed: Frontal shield total L/medial L/W 430/240/400; swimming setae II-L-4/ 5 2/10; III-L-3/4/5 2/9/15; IV-L-3/4/5 4/12/15; genital flap L 230, Ac-1/-2/-3 L 40/35/ 50; gnathosoma/rostrum L 210/60; chelicera basal segment/claw L/H 250/100/105; P-1-5 L/H (segments probably squeezed and therefore H measurements higher than under natural conditions) 50/85, 115/108, 70/ 95, 155/65, 35/20, palp total L 425, P-2/P-4 ratio 0.74, setation P- 1-4 2, 10, 4, 3. The specimen agrees well with H. dispar , not only in the shape of the frontal shield and mouth parts, but also in swimming setae numbers. Therefore, H. algeriensis is synonymized here with H. dispar . In the Mediterranean area, H. dispar is obviously a rare, but widely distributed pond-dwelling species.