UPDATE: After reading the recently published article about the new freshwater crab genus Cantopotamon, the crabs I found are certainly Cantopotamon zhuhaiense, described from the exact locality where I found them. Here is the link to this article:
zoolstud.sinica.edu.tw/Journals/56/56-41.pdfThe crabs were found in fast to slow-flowing hill streams on altitudes between 50 and 300 meters above sea level. They hide under stones and were occasionally observed leaving the water and climbing rock. At no site C. zhuhaiense was seen thriving sympatrically with the other Potamid I saw, Nanhaipotamon guangdongense, although in the original description, they were observed living in the same habitat as Nanhaipotamon zhuhaiense and N. guangdongense. Nevertheless, N. guangdongense was present in very small to small, more slow-flowing streams with sandy, muddy, or clay bottom, whereas C. zhuhaiense was found in broader, fast-flowing streams on gravel or sandy bottom.Zhuhai, Guangdong Former Text:The freshwater crab genus Candidiopotamon is to date only known from Taiwan and the Ryukyu Islands. The species described from Guangdong province by Dai, 1999 is now considered a synonym of C. rathbunae from Taiwan (See Shih & Ng, 2011).Nevertheless, I found a few specimens resembeling no other Potamids from Guangdong province that I am aware of, but bear similarity to C. rathbunae. For no better name, the specimes are labeled C. cf. guangdongense. It is possible that there is a population of C. rathbunae or a new unknown species in Guangdong. Perhaps, the crabs I found belong to yet another species described by a single or few specimens from unknown localities in Guangdong, as Yarepotamon guangdongense. The only dorsal image of Y. guangdongense I was able to find is in black and white and really small, and as I did not take an image of the male Gonopod or Maxilliped 3, there is no way to finally determine the status of the photographed specimen (link to the article here:
lkcnhm.nus.edu.sg/app/uploads/2017/06/45rbz237-264.pdf).
