Nanhaipotamon

Nanhaipotamon is a genus of freshwater crabs, in the subfamily Potamiscinae, found in southern China and Taiwan. As of 2018, 18 species have been described. The genus is named after the South China Sea (; literally: 'South Sea'), for it occurs mostly in coastal areas. The genus was first described by R. Bott in 1968 as Isolapotamon (Nanhaipotamon), i.e., a subgenus of Isolapotamon.

== Description == These crabs are relatively large, with a carapace breadth of up to . Depending on the species, the carapace may be vividly coloured, especially in males of N. hongkongense (orange to red),'' N. aculatum (dark blue) and N. zhuhaiense (light blue). Chelipeds are usually unequal, more so in larger males, where one cheliped is relatively much larger than the other. This may be of use in territorial fights, as the crabs are very aggressive towards conspecifics.