Contributions to Chinese fauna of Torrenticolidae Piersig, 1902 (Acari, Hydrachnidia), with the description of three new species

Abstract Five species of torrenticolid mites (Acari, Hydrachnidia), collected in the Anzihe and Qingliangfeng national nature reserves, R. P. China, are identified. Three species are described as new to science: Torrenticola pseudosiamis Gu & Guo, sp. nov., T. anziensis Gu & Guo, sp. nov., and Monatractides sichuanensis Gu & Guo, sp. nov. The other two species, M. macrocorpis Gu & Guo, 2019, M. xiaoxiensis Gu & Guo, 2019, are newly reported from Zhejiang Province. Descriptions and illustrations of these species are included.


Introduction
China is rich in ecological diversity and types of water bodies, which suggests that a rich species diversity of water mites is expected in the Chinese fauna. In the number of species, the family Torrenticolidae is one of the largest groups of water mites. Until now, the total number of torrenticolid mites is about 600 worldwide, but only 38 species are known from China, including the three new species added in this paper (Gu et al. 2019a(Gu et al. , 2020a. This means that the Chinese torrenticolid mites fauna is largely unknown, and the identification of Chinese torrenticolid species will be a focus in the near future.
In this paper, five species of Torrenticolidae are identified from two national nature reserves in China, Anzihe National Nature Reserve in Sichuan Province and Qingliangfeng National Nature Reserve in Zhejiang Province. Three of these species are new to science: Torrenticola pseudosiamis Gu & Guo, sp. nov., T. anziensis Gu & Guo, sp. nov., and Monatractides sichuanensis Gu & Guo, sp. nov. The other two are newly reported from Zhejiang Province: M. macrocorpis  and M. xiaoxiensis . These five species are described and illustrated here.

Material and methods
Water mites were collected, preserved, cleaned, and mounted following the usual methods (Jin 1997;Ding et al. 2019).

Habitat. Streamlet.
Remarks. Due to the characteristic shape of gnathosoma and dorsal shield (i.e., gnathosoma with a short rostrum, the lateral view of gnathosoma regular triangle-like), this new species is similar to Torrenticola siamis Smit, 2009 (Pešić andSmit 2009). However, there are obvious differences between them: (1) only the tip of Cx-I exceeding to the anterior margin of idiosoma in this new species, but the tip of Cx-I and Cx-II exceeding in T. siamis; (2) E 4 at the same level as the 6 th pair of acetabula in the new species, but the 4 th pair in T. siamis; (3) D 2 on the same level with muscle scars in the new species, but D 2 anterior to muscle scars in T. siamis.
Etymology. The specific name is from Latin affix: "pseudo-", which means fake or simulated; this new species is named after its similar species, T. siamis.

Torrenticola anziensis
Etymology. This new species is named after Anzi (Anzi River), where the new species was collected.