Arrenurus (Micruracarus) contortus, Pešic & Smit, 2016

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 : 432

publication ID 10.1051/acarologia/20162251


persistent identifier

treatment provided by


scientific name

Arrenurus (Micruracarus) contortus

n. sp.

Arrenurus (Micruracarus) contortus n. sp.

( Figure 24 View FIGURE )

Type series — Holotype male, dissected and slide mounted, Vietnam, 15-44-1 Bach MAE National Park, brook with a pool behind a natural barrier, 16°11’15.5"N, 105°50’54.7"E, alt. 1130 m a.s.l., water depth 0.2 m, substrate: leaves in a lentic bay, 2.v.2015. GoogleMaps

Diagnosis — Petiole consisting of hyaline appendages; posterior dorsal margin with a pair of double-lobed hyaline membranes; genital plates reversed wing-shaped, broadening laterally; gonopore very narrow.

Description — Male: Idiosoma lilac, dorsally 603 long and 543 wide. Dorsal shield complete, 381 wide. Dgl-3, Dgl-4 and Lgl-4 (conform Wiles 1997) not well visible in dorsal view due to bowing of the dorsal shield. Pygal lobes absent. Posterior dorsal margin with a pair of two-lobed hyaline membranes. Posterior margin ending in a blunt, rounded projection, flanked by a pair of knob-like extensions. Cx-I extending beyond anterior idiosoma margin. Distance of tip of Cx-I to posterior idiosoma margin 640 µm. Genital plates reversed wing-shaped, broadening laterally, slightly extending onto lateral idiosoma margin. Gonopore very narrow, 60 µm long. Idiosoma posteromedially with a concavity, with the petiole in it. Petiole consisting of two hyaline appendages, their shape dependent on position of the specimen. Besides the hyaline petiole a double-tipped hyaline appendage present. Palp: total L 214, dL: P-1, 28; P-2, 52; P-3, 42; P-4, 54; P-5, 38; P-2 medially with four setae, dorsally with three setae; P-3 with a long medial seta. Legs: dL of I-L-4-6: 86, 86, 76; dL of IV-L-4-6: 122, 112, 92; IV-L-4 without a spur. Third and fourth legs with numerous swimming setae. Female: Unknown.

Etymology — Named for the complicated structure of the appendages.

Remarks — The shape of the genital plates is very unusual, and thus far found in the subgenus Rhinophoracarus Viets, 1916 and in a small number of other subgenera. However, members of Rhinophoracarus have a very long petiole, very unlike the hyaline petiole of the new species. Due to the presence of a hyaline petiole and hyaline appendages assignment to Micruracarus seems most appropriate.

Distribution — Vietnam; only known from the locus typicus ( Figure 25C View FIGURE ).