Blind cave fish discovered at Phong Nha – Ke Bang and Hin Nam No heritage sites

On July 25, Mr. Pham Hong Thai, Director of Phong Nha – Ke Bang National Park (Quang Tri province), said that conservation experts have discovered a species of eyeless fish living in underground rivers belonging to the Phong Nha – Ke Bang trans-border heritage cluster (Vietnam) and Hin Nam No (Laos).

The species has been provisionally named the blind cave fish, a species endemic to completely dark environments where light cannot penetrate limestone layers hundreds of millions of years old.

Blind cave fish in Phong Nha - Ke Bang and Hin Nam No

Cave blind fish lack eyes, a characteristic of creatures that have evolved in environments with prolonged lack of light. Instead of vision, they have developed the ability to sense vibrations and water pressure through an extremely sensitive system of fins and whiskers, thereby locating prey, currents, and objects in the harsh cave environment.

The first individuals were recorded living in Son Doong Cave, Va Cave, Hung Thong Cave in Phong Nha – Ke Bang National Park. Meanwhile, on the Lao side, Xe Bang Fai Cave in Hin Nam No area is also where traces of a similar blind fish species were discovered.

Blind fish in Phong Nha - Ke Bang area

According to Mr. Thai, the fact that blind fish were found on both sides of the Vietnam-Laos border is an important indicator confirming the ecological connection between the two adjacent heritages. Both Phong Nha-Ke Bang and Hin Nam No are located in ancient limestone blocks hundreds of millions of years old, where a complex and closed underground river network and caves have formed, creating conditions for the formation of biological populations isolated from the outside world .

Currently, American scientists are working with local experts to collect blind fish samples from two cave systems to decode their DNA, to determine whether they belong to the same species or two separate evolutionary branches, which is not only meaningful in biological classification but also reveals the process of isolated evolution in closed caves.

If confirmed as conspecific, it would be one of the few organisms to be recognised as endemic to transboundary heritage, with enormous significance for biodiversity conservation.

MINH PHONG

Source: https://www.sggp.org.vn/phat-hien-ca-mu-hang-dong-tai-di-san-phong-nha-ke-bang-va-hin-nam-no-post805416.html