Feihu Dong, a New Hotspot Cave of Subterranean Biodiversity from China

Abstract

China is a country with abundant karst landscapes, but research on cave biodiversity is still limited. Currently, only Ganxiao Dong, located in Huanjiang, Guangxi, has been reported as a hotspot for cave biodiversity. Many of the world’s most troglomorphic species in the major groups of cave animals have been recently discovered in China, making the existence of many more hotspots in the country likely. Feihu Dong, one of these potential hotspot caves, has been systematically investigated to complement a preliminary species list of 1995, leading to the discovery of 62 species of animals from the cave. Among them, 27 are considered troglobionts or stygobionts, 26 are considered troglophiles or stygophiles, and nine are classified as trogloxenes or stygoxenes. Research on the cave biodiversity of Feihu Dong has demonstrated that it currently holds the highest number of known cave animal species in China. Among the most remarkable features of this fauna is the co-occurrence of five species of cave-obligate beetles, all modified for cave life. The biological survey was limited to a small part of the cave. Several habitats (like guano) have not been investigated so far, and several important cave groups have been insufficiently or not sampled (like Ostracoda). Meanwhile, the system increases in length with each new caving expedition. Further discoveries of cave organisms in Feihu Dong are therefore expected. As Feihu Dong and Ganxiao Dong are the only caves in China that have been extensively studied for a large range of organisms, and as they are located in karstic areas that are similar in richness to other regions of southern China, it can be confidently assumed that several other caves of high biodiversity will be discovered in the coming years.

Global Subterranean Biodiversity: A Unique Pattern

“…Three of them were treated as hotspots in the two Special Issues of Diversity, as they host more than 25 such species (Towakkalak System in Indonesia, Tham Chiang Dao in Thailand and Hang Mo So in Vietnam). Nine other caves scattered in the lowlands of the same region have between 15 and 24 cave-restricted species: Batu Caves in Malaysia [107] and Saripa Cave in Sulawesi, Indonesia [37] with 24 species, Clearwater Cave in Sarawak [108] with at least 22 species, Ganxiao Dong in Southern China [30] and the Sangki System in Sumatra, Indonesia [71] with 20 species, Ma San Dong in Southern China [71] with 17 species, Batu Lubang in Halmahera, Indonesia [71] and Tham Thon in Laos [71] with 16 species, Tham None in Laos [71] with 15 species. Several other caves which have been well sampled are much less rich than those cited above.…”

The Diversity of Subterranean Terrestrial Arthropods in Resava Cave (Eastern Serbia)

“…Similar phenomena of karstification and the development of a rich subterranean fauna also occurred on other continents, as recent studies on subterranean biodiversity in North America [8] and South America [9] confirm. Finally, the Asian limestone masses are the most impressive, with only the vast karst area in southern China, covering some 550,000 km 2 [10], having the greatest potential to be the world's largest hotspot of subterranean diversity with many specialized hypogean taxa [11,12]. Recently, numerous taxa from the karst of China have been described as new to science [13,14].…”

A Hotspot of Subterranean Biodiversity on the Brink: Mo So Cave and the Hon Chong Karst of Vietnam

“…Long caves with underground rivers are generally those richest in biodiversity [1], such as Mammoth Cave in USA [2], the Postojna-Planina Cave System in Slovenia [3], Ojo Guarena in Spain [4], Feihu Dong in China [5], the Towakkalak system in Sulawesi [6] or Agua Clara in Brazil [7]. The MDL caves are quite different: they are short and shallow, without active hydrological circulation, and are supplied with large amounts of nutrients (roots, guano, debris) due to surface proximity.…”