Hydrodroma liberiensis Cook, 1966

Gerecke, Reinhard, 2017, The water mites of the genus Hydrodroma (Acari, Hydrachnidia, Hydrodromidae) in Europe and Africa, Ecologica Montenegrina 13, pp. 1-24 : 18-19

Hydrodroma liberiensis Cook, 1966

( Figs 7 A-B)

Type series: FMC, holotype ♂ and paratype ♀, slide mounted; locality information "DC 36" incised on the slide [ Cook 1966: Stream at bridge 19 on Bomi Hills Road , Jan. 23, 1957 " ].

Discussion: This species is highly distinct in its generally reduced size (e.g. idiosoma L ♂ 550, ♀ 700; CxI+II ♂ 150, ♀ 160; genital plate ♂ 120, ♀ 140) and a low acetabula number (♂ 25, ♀ 33 pairs). Also segments of mouthparts and legs are by far shorter than in all compared species (e.g., L I-L-4, ♂ 105, ♀ 115; IV-L-5, ♂ 200, ♀ 210; P-4, ♂ 93, ♀ 110). Obviously, H. liberiensis is a typical inhabitant of lotic habitats characterized by relatively strong leg claws (leg claw L 16-22 % segment 5 L), and strongly reduced swimming setation (total number 10-11, no segment with anterior setae, posterior setae numbers: II-L-5, 0-1; III-L-4, 2-3; III-L-5, 2-3; IV-L-4, 2-3; IV-L-5, 2-3). The integument structure is rather characteristic, with a distinct, two-type papillosity: each of the very flat, slightly posterior directed principal papillae is surrounded by six well visible secondary minor papillae ( Figs 7 A-B).

Distribution: Only known from the type locality and four further sites in Liberia ( Cook 1966)

Figures

Figure 7. A-B. Hydrodroma liberiensis, integument papillae in tangential and top view. A. holotype male; B. paratype female. C.-H. H. rheophila, female from Lesbos (photographs and drawings: Vladimir Pešić). C. integument in tangential view; D. integument in top view (magnification as in C.); E. palp; F. II-L-4-5; G. III-L-4-6; H. IV-L-4-6.