| abstract | Arrenurus is considered one of the most specious genera of water mites. This paper deals with three species of Arrenurus Dugès, 1834 (Acari, Hydrachnidiae, Arrenuridae) from Delingha, Qinghai Province, PR China. Arrenurus (Arrenurus) jaggedis sp. nov. is new to science; Arrenurus (Arrenurus) affinis Koenike, 1887 and Arrenurus (Arrenurus) turgidus Koenike, 1911 are recorded for the first time for the Chinese fauna. Arrenurus (Arrenurus) jaggedis sp. nov. can be distinguished by the petiole with furrows at the end, lateral ridges jagged, dorsal humps well developed, the top sharp and curved towards the front edge of the body. Detailed descriptions and illustrations of the new and newly recorded species are given in this paper. |