A new genus and new species, Montinumen cryptovium gen. nov. et sp. nov. (Crustacea: Decapoda: Potamidae), the first cave-dwelling freshwater crab in Yunnan, Southern China

A new genus and new species of freshwater crab, Montinumen cryptovium gen. nov. et sp. nov., is described from Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan Province, southern China based on morphology and mitochondrial 16S rDNA sequences. This is the first record of a cave-dwelling freshwater crab species in Yunnan province. This species has elongated pereiopods and relatively smaller eyes, but its pigmentation and corneas do not exhibit troglobitic features. Montinumen cryptovium gen. nov. et sp. nov. superficially resembles Tiwaripotamon Bott, 1970, but it can be easily distinguished by the form of its carapace, third maxilliped, and male first gonopod. Molecular data derived from mitochondrial 16S rDNA supports the establishment of this new genus.