Native researcher of Hengqin unveils new crab genus

A previously unknown freshwater crab genus, Cantopotamon hengqinense, has been discovered on Hengqin Island. It is featured in the Dec 20, 2017 edition of the Taiwan bimonthly journal Zoological Studies.

Zhuhai native Huang Chao, a doctoral candidate in biology in Australia, is the lead researcher in the discovery. His team's observations and research are detailed in the paper Cantopotamon, a New Genus of Freshwater Crabs From Guangdong, China, With Descriptions of Four New Species (Crustacea: Decapoda: Brachyura: Potamidae), Chao Huang, Shane T Ahyong, and Hsi-Te Shih.

The publication associates Huang with the Palaeontology, Geobiology & Earth Archives Research Centre, School of Biological, Earth & Environmental Sciences, University of New South Wales; Australian Museum; and School of Life Sciences, Sun Yat-sen University, Guangzhou.

Cantopotamon hengqinense

The new cast of crabs was only spotted in three of Da Hengqin Mt streams; their combination of clean water and intact vegetation being the most suitable habitat.

In Huang's observation, the crabs have brown dorsal exoskeletons and are relatively smaller than related species. The diameter of an adult Cantopotamon hengqinense carapace is about the size of a one-yuan coin, or 25 mm. They hide in the shadows of stones and rock crevices.

According to the Red List Categories & Criteria formulated by the International Union for Conservation of Nature & Natural Resources (IUCN), the crab species should be classified as endangered. Once approved, the threat level faced by them would be higher than that for giant pandas, according to Huang.

Kadoorie Conservation China, a department under biodiversity-conservation group Kadoorie Farm & Botanic Garden in the New Territories of Hong Kong, spoke about Hengqin's unique location and ecological niche on Sina Weibo (a Chinese version of Twitter). It pointed out that varied ecological environments create tremendous diversity of life.

Huang did field collections and initiated the manuscript, which states, "The discovery of new taxa of freshwater crabs continues at a significant rate, especially in China and India."

In India, A Biju Kumar, professor at the University of Kerala, told the Deccan Chronicle last fall: "Crabs are not migratory, and their distribution is limited. So, there could be many more freshwater species endemics to each river basin."

Meanwhile, other rare species inhabit Hengqin Island and surroundings. They include the Sousa chinensis -- Chinese white dolphin; Lutra lutra -- Eurasian otter; and Haliaeetus leucogaster -- white-bellied sea eagle.

Da Hengqin Mt stream [Photos courtesy Zhuhai Daily]