China : Discovery of a new “eyeless” creature in an underwater cave

-
A team of researchers discovered a pink, eyeless creature in an underwater cave in China, which may explain some mysteries about the evolution of creatures.

Researchers from Huazhong University of Science and Technology, the Chinese Academy of Sciences, and several local wildlife agencies announced a new type of cave fish that lives deep in the subterranean streams of the Wujiang River system. It is characterized by being blind and its eyes appear as black dots under its skin.

However, some fish of this species appeared to have poor vision, which may provide "exceptional cases for evolutionary studies."

The research team named the discovered species "Guiyang Golden-line Barbel", or Sinocyclocheilus guiyang, and said: "We have not paid attention to the fish diversity in the Yangtze River basin in Guiyang City, the most urbanized area in Guizhou, for a long time."

The geology of the Wujiang River system, in central Guizhou Province, consists mainly of limestone and other carbonate rocks known as karst, which dissolve easily in water creating streams across this region of south-central China.

“The Wujiang River system also exhibits extensive and well-developed karst forms, which provided good conditions for the formation of subterranean river systems,” the researchers wrote. “Extended arms in Sinocyclocheilus species are common, as long arms better detect water flow and help forage for food in subterranean water systems.” It is characterized by constant darkness and scarcity of food.”

The new cavefish has “damaged” scales, an overall shorter snout and shorter fins than other Sinocyclocheilus species, and has a bright golden mark on its back between its head and dorsal fin, the team reported in the journal Zoosystematics and Evolution.

While there are more than 200 scientifically documented species of "blind" and/or "cave" (cave-dwelling) fish worldwide, found on every continent except Antarctica, each individual species comes in limited numbers.

The research team hopes that further research will help protect these creatures from extinction.