Hygrobates (Hygrobates) cf. sinensis Uchida & Imamura, 1951

Pešic, V. & Smit, H., 2016, New records of water mites from Southeast Asia (Acari: Hydrachnidia) with the description of two new genera and 12 new species, Acarologia 56 (3), pp. 393-433 : 403-407

Hygrobates (Hygrobates) cf. sinensis Uchida & Imamura, 1951

( Figure 8 )

Material examined — Vietnam, 15-51-1, Mekong delta at Can Tho, Mekong river , shore, near ferry landing place, 10°03’43"N, 105°47’02"E, alt. 1 m a.s.l., water depth 0.2-0.5 m, substrate: greyblack sand, Eichhornia crassipes , 7.v.2015, 0/1/0 (mounted) .

Morphology — Female: Integument finely striated. Posteromedial margin of Cx-I slightly concave; Cx-IV subtriangular in shape, with anterior and posterior margins converging to median line. Gonopore very long, genital plates short, restricted to the level of postgenital sclerite, acetabula in triangular position ( Figure 8A ). P-2 ventral margin concave, distally protruding in a slightly knob-shaped projection covered by large, scattered denticles; P-3 with a few large and scattered ventral denticles in the distal part ( Figures 8 E-F); P-4 ventral setae separation 14 µm. Swimming hairs absent.

Measurements —Idiosoma L 610; coxal field: L 252, Cx-III W 334, Cx-I+II mL 194; genital field L/W 185/209, genital plate L/W 62-63/41, gonopore L 163. Palp: total L 298, dL/H, dL/H ratio: P-1, 24/29, 0.84; P-2, 85/51, 1.67; P-3, 51/45, 1.14; P-4, 94/31, 3.1; P-5, 44/15, 2.9; L ratio P-2/P-4, 0.9; chelicera total L 220. Legs: dL of I-L-2-6: 71, 65, 85, 89, 101; dL of IV-L: 88, 68, 105, 149, 155, 158.

Remarks — The single female from Vietnam matches the general morphology of Hygrobates sinensis Uchida & Imamura, 1951 from China. However, only a single female was taken, so our record should be considered tentative until males are examined.

Distribution — China, Vietnam.

Figures

FIGURE 8: Hygrobates (Hygrobates) cf. sinensis Uchida & Imamura, 1951, female, Mekong River, Vietnam: A – idiosoma, ventral view; B – chelicera; C – III-L claw; D – I-L-2-6; E-F – palp. Scale bars – 100 µm.