New records of water mites of the family Torrenticolidae (Acari, Hydrachnidia) with descriptions of two new species from Nanshih River system in Taiwan and redescription of Torrenticola ussuriensis (Sokolow, 1940) from the Russian Far East

Abstract

New records of torrenticolid water mites (Acari: Hydrachnidia, Torrenticolidae) from Nanshih River, Taiwan, are presented. Two new species are described: Torrenticola nanshihensis and Torrenticola taiwanicus; the latter species is compared with Torrenticola ussuriensis (Sokolow, 1940), a poorly known species which is re-described based on a new material from the Russian Far East; Monatractides cf. circuloides (Halík, 1930)is reported for the first time for Taiwan.

Keywords: Acari; Nanshih River system; Taiwan; new species; running waters; water mites.

Figure 1.

Map of the study area, showing location of sampling sites (black circles).

Figure 2.

Torrenticola taiwanicus sp. n., male: A dorsal shield B ventral shield C palp (P-1 missing), medial view D palp (P-1 missing), lateral view. Scale bars = 100 µm.

Figure 3.

Torrenticola taiwanicus sp. n., female: A ventral shield B palp (P-1 missing), medial view C capitulum. Scale bars = 100 µm.

Figure 4.

A–B: Torrenticola ussuriensis (Sokolow, 1940)(A male, B female), dorsal shield; C–D: Torrenticola taiwanicus sp. n. (C male, D female), dorsal shield.

Figure 5.

Torrenticola ussuriensis (Sokolow, 1940) (A–B, D male, C female): A dorsal shield B–C ventral shield D capitulum and palp, lateral view. Scale bars = 100 µm (A–C), 25 µm (D).

Figure 6.

Torrenticola nanshihensis sp. n., male: A dorsal shield B ventral shield C gnathosoma D palp (P-1 missing), medial view E palp (P-1 missing), lateral view. Scale bars = 100 µm.

Figure 7. SEM photographs. A Torrenticola taiwanicus sp. n., female: A ventral view of idiosoma and gnathosoma, scale bar = 200 μm. B–D Monatractides cf. circuloides (Halík, 1930), male: B dorso-lateral view of idiosoma and gnathosoma, scale bar = 500 μm C ventral view of idiosoma and gnathosoma, scale bar = 500 μm. D ventral view of gnathosoma and anterior part of idiosoma, scale bar = 200 μm.