Sinocyclocheilus donglanensis (Donglan golden-line barbel) is a species of cave fish in the family Cyprinidae. It is endemic to Guangxi province in southern China, and only known from a subterranean tributary of the Hongshui River, a tributary of the Pearl River. Its specific name donglanensis refers to the Donglan County where its type locality is located. It is not known from elsewhere.

Description
Sinocyclocheilus donglanensis grows to  standard length; mean length of five individuals was . The head is compressed and has developed eyes. The mouth has two barbels and is slightly inferior, with the upper jaw that protrudes slightly beyond the lower one. The body is compressed and completely scaled. The highest body depth (about 31% of standard length) occurs exactly at the dorsal fin insertion. The lateral line is complete and curved. In preservative, the colour of the back is dark brownish; the abdomen is light grayish. Pelvic and anal fins are light yellowish.

It resembles morphologically most closely Sinocyclocheilus yishanensis known from the Liu River, another river in the Pearl River system. Both have "normal" body shape, in contrast to some other Sinocyclocheilus species showing humps or horns.

Ecology and behaviour
Virtually nothing is known about the ecology and behaviour of this species. It shares its habitat (and type locality) with another cave fish species, Sinocyclocheilus altishoulderus.

Habitat and conservation
The type locality, near Gongping Village, Taiping Town, Donglan County, is a subterranean river some 10–20 metres inside from the mouth of a small cave. During the rainy season, the water can extend outside the cave to form a small lake. The habitat is potentially threatened by water extraction, waste disposal and pesticide pollution, and landscape alterations in general.

References 

Cave fish
donglanensis
Endemic fauna of Guangxi
Freshwater fish of China
Cyprinid fish of Asia
Fish described in 2006