Nanhaipotamon hongkongense

Description:

Until now, the semi-terrestically freshwater crab Nanhaipotamon hongkongense was due to lack of better distribution knowledge considered a Hong Kong endemic. During a night walk in Shenzhen, however, I found crabs resembling the phenotype of N. hongkongense, so this species is most probably distributed in the southern parts of Guangdong, as well. Other than N. guangdongense, which was abundant and not too hard to observe at some sites in Zhuhai, I was not able to find a site where N. hongkongense was similarly abundant. The crabs tend to flee and hide in their burrows at the slightest disturbance and may therefore be more cryptic than allied species in southern China. Of all Nanhaipotamon species, N. hongkongense is the most traded in pet markets even in Europe because of its variable and signalling red or orange colour and vivid behaviour.Collections of wild animals may pose a threat to current populations in Hong Kong. This and a cryptic life history may be the reason why they did not seem to be as abundant as N. guangdongense.Wutong Shan, Shenzhen, China.