Hygrobates (Hygrobates) henni Wiles, 2004

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

Hygrobates (Hygrobates) henni Wiles, 2004

( Figure 7 )

Material examined — Laos, 15-32-1, Kouangxi Waterfall, pond behind a artificial barrier within a branch near the main brook, 19°44’56"N, 101°59’33"E, alt. c. 490 m a.s.l., water depth 0.4 m, substrate: travertine mud covered by a thick layer of leaves, 21.iv.2015, 1/0/0 (mounted) .

Morphology — Male: Integument papillate ( Figure 7B ). Posteromedial margin of Cx-I broadly rounded. Cx-IV with a distinct nose-like protruding medial margin. Genital plate anterior margin with a small knob-shaped medial projection projecting in a deep indentation, posterior margin deeply indented with a small protrusion in the centre of indentation; acetabula in a triangular arrangement, Ac-2 and Ac- 3 on the same level ( Figure 7A ). P-2 ventral margin proximally almost straight, distoventrally protruding in a long and slender projection, apically covered by a few small denticles; P-3 distally with 7- 8 larger denticles covering more than half of ventral margin ( Figures 7 E-F); P-4 slender, ventral setae close to each other (separation 22 µm).

Measurements — Idiosoma L/W 713/637; coxal field L/W 331/522, Cx-III W 406; genital plate L/W 166/213, ratio 0.78; ejaculatory complex L 132. Palp: total L 378, dL/H, dL/H ratio: P-1, 30/36, 0.83; P- 2, 97/65, 1.5; P-3, 77/57, 1.35; P-4, 126/31, 4.1; P- 5, 48/16, 2.9; L ratio P-2/P-4, 0.77; chelicera total L 254, claw L 90, basal segment L 170, L basal segment/claw ratio 1.9. Legs: dL of I-L-5-6 ( Figure 7C ): 135, 130; dL of IV-L: 113, 94, 131, 194, 213, 163.

Remarks — The single male from Kauangxi Waterfall matches the general morphology of Hygrobates henni Wiles, 2004 . This species was described by Wiles (2004) from Mai Yim waterfalls in Thailand.

Distribution — Previously known only from Thailand, and here reported for the first time for Laos.

Figures

FIGURE 7: Hygrobates (Hygrobates) henni Wiles, 2004, male, Kauangxi Waterfall, Laos: A – idiosoma, ventral view; B – details of dorsal integument; C – I-L-5 and -6; D – chelicera; E-F – palp. Scale bars – 100 µm.