The waterfall climbing cave fish (''Cryptotora thamicola''), also known as the cave angel fish, is a species of

troglobitic A troglobite (or, formally, troglobiont) is an animal species, or population of a species, strictly bound to underground habitats, such as caves. These are separate from species that mainly live in above-ground habitats but are also able to live u ...

hillstream loach The hillstream loaches or river loaches are a family, the Balitoridae, of small fish from South, Southeast and East Asia. The family includes about 202 species. They are sometimes sold as "lizardfish" or (in Germany) "flossensaugers". Many of the ...

endemic to

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bo ...

. It reaches a length of SL. This fish is known for its fins, which can grapple onto terrain, and its ability to climb. This fish is the only known member of its

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

. The species has been recorded from eight subterranean sites within a large karst system (Pang Mapha karst formation) in

Mae Hong Son Province Mae Hong Son province ( Burmese: မဲဟောင်ဆောင်; th, แม่ฮ่องสอน, ; Northern Thai: ; Shan: ; formerly called ''Mae Rong Son''), also spelled ''Maehongson'', ''Mae Hong Sorn'' or ''Maehongsorn'', is one of ...

, Thailand. The species has an extent of occurrence of nearly 200 km², but an area of occupancy of 6 km²; the connectivity of this karst systems is unknown, some caves are definitely connected. The species is found in eight of the caves. It has been recorded from the Susa (from where it was first collected in May 1985) and Tham Mae Lana (Borowsky and Vidthayanon 2001). It may also occur in other submerged caves in the area. However, the species has a potential threat of

agricultural pollution Agricultural pollution refers to biotic and abiotic byproducts of farming practices that result in contamination or degradation of the environment and surrounding ecosystems, and/or cause injury to humans and their economic interests. The pol ...

which could impact the whole karst system, making it one location. Like other

cavefish 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 ...

, it is depigmented and has no visible eyes. This species coexists with another

hypogean Hypogeal, hypogean, hypogeic and hypogeous (; ) are biological terms describing an organism's activity below the soil surface. In botany, a seed is described as showing hypogeal germination when the cotyledons of the germinating seed remain n ...

(underground-living) loach, '' Schistura oedipus''. The species is specialized for fast subterranean flowing water in the deeper zone of the cave (more than 500m from the entrance). It depends on cave microorganisms and organic matter, and is very sensitive to disturbance, water quality and hydrographic change. The species is protected under Thai law, and is found within a National Park (Pai Basin NP), but this does not necessarily protect the species as there is little restrictions on agricultural practices and regulation of tourism is needed to reduce the potential impacts to the species habitat at some sites. Human disturbance from tourism activity (some of the habitat sites are popular for caving tourism and sightseeing) may threaten the species. Agriculture and deforestation are future major threats. In 2016 it was reported that the waterfall climbing cave fish walks with a

tetrapod Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct theraps ...

-like diagonal-couplets lateral sequence gait, displaying a robust

pelvic The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

girdle attached to the

vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordata, ...

References

External links

Fish That Walks
NYTimes, March 27, 2016 * {{Taxonbar, from=Q3314215 Balitoridae Cave fish Monotypic fish genera Fish of Thailand Endemic fauna of Thailand Taxa named by Maurice Kottelat Fish described in 1988 Taxonomy articles created by Polbot