Chinese scientists have discovered another wild population of the White Cloud Mountain minnow, Tanichthys albonubes, in the southern Chinese island of Hainan.
In a study published in the most recent issue of the journal Zoological Research, Bosco Chan and Xiang-Lin Chen report the discovery of a wild population of White Cloud Mountain minnows from a single site in Hainan Island off the coast of southeastern China.
Although easily available in the aquarium trade as farm-bred fish, the White Cloud Mountain minnow is exceptionally rare in the wild; the species was thought to be extinct in the wild until populations from Quang Ninh province in Vietnam and from Guangdong Province, southern China were rediscovered (see White Clouds in danger).
The Hainan population of the White Cloud Mountain minnow, which is the first known from an island, was found in ...a clean, meandering, sluggish coastal stream and its small tributaries. The stream has a sandy/pebble substrate, and fallen leaves sometimes accumulate on the stream-bed.
The authors found the fish to form ...shoals in backwaters and sluggish sections of the stream, and always stay close to some cover, most frequently among trailing vegetation along the banks.
The authors also found the fish to be less tolerant of low temperatures compared to aquarium-bred strains, dying off when water temperatures reached below 15C during a cold spell (the aquarium-bred strains remained unaffected).
The authors did not reveal the exact location of the site in order to safeguard this population from collectors and are working with authorities to protect the site.
For more information, see the paper: Chan, BPL and X-L Chen (2009) Discovery of Tanichthys albonubes Lin 1932 (Cyprinidae) on Hainan Island, and notes on its ecology. Zoological Research 30, pp. 209"214.