''Sinocyclocheilus donglanensis'' (Donglan golden-line barbel) is a species of

cave fish Cavefish or cave fish is a generic term for fresh and brackish water fish adapted to life in caves and other underground habitats. Related terms are subterranean fish, troglomorphic fish, troglobitic fish, stygobitic fish, phreatic fish and hypog ...

in the family

Cyprinidae Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest verte ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Guangxi Guangxi (; ; Chinese postal romanization, alternately romanized as Kwanghsi; ; za, Gvangjsih, italics=yes), officially the Guangxi Zhuang Autonomous Region (GZAR), is an Autonomous regions of China, autonomous region of the People's Republic ...

province in southern China, and only known from a subterranean tributary of the

Hongshui River The Hongshui River is a major river in the Guangxi Zhuang Autonomous Region in Southern China. It is one of the main rivers in the basin of the Xi River, which in its turn is one of the main tributaries of the Pearl River. Because it flows thr ...

, a tributary of the

Pearl River The Pearl River, also known by its Chinese name Zhujiang or Zhu Jiang in Mandarin pinyin or Chu Kiang and formerly often known as the , is an extensive river system in southern China. The name "Pearl River" is also often used as a catch-all ...

. Its specific name ''donglanensis'' refers to the

Donglan County Donglan County (, Zhuang: ) is a county of northwest Guangxi, China. It is under the administration of Hechi City. Donglan County has given its name to the Donglan golden-line barbel ('' Sinocyclocheilus donglanensis''), a small fish that is onl ...

where its type locality is located. It is not known from elsewhere.

Description

''Sinocyclocheilus donglanensis'' grows to

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

; 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 A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

insertion. The

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

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 The Liu River (, pinyin: Liǔ Jiāng, literally: ''Willow River'') is a tributary within the Pearl River system in Guangxi, China. It is formed by the confluence of the Rong and Long rivers in Fengshan. It flows south through Liuzhou and then t ...

, 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 ''Sinocyclocheilus altishoulderus'' (common name: high-shoulder 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 cave in Donglan County, from a sub ...

''.

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 The environmental effects of pesticides describe the broad series of consequences of using pesticides. The unintended consequences of pesticides is one of the main drivers of the negative impact of modern industrial agriculture on the environme ...

, and landscape alterations in general.

References

{{Taxonbar, from=Q3768723 Cave fish donglanensis Endemic fauna of Guangxi Freshwater fish of China Cyprinid fish of Asia Fish described in 2006