The greater scissortail (''Rasbora caudimaculata'') is a species of

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

in the genus ''

Rasbora ''Rasbora'' is a genus of fish in the family Danionidae. They are native to freshwater habitats in South and Southeast Asia, as well as southeast China. A single species, ''R. gerlachi'', is only known from an old specimen that reputedly origina ...

''. It inhabits forest creeks in

Malaysia Malaysia is a country in Southeast Asia. Featuring the Tanjung Piai, southernmost point of continental Eurasia, it is a federation, federal constitutional monarchy consisting of States and federal territories of Malaysia, 13 states and thre ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

and the lower

Mekong The Mekong or Mekong River ( , ) is a transboundary river in East Asia and Southeast Asia. It is the world's twelfth-longest river and the third-longest in Asia with an estimated length of and a drainage area of , discharging of wat ...

basin.

Local names

* Called Betelah by the Merap community * Called Beteluh by the Punan community * Called Beteloh by the Kenyah community * Called Seluang Engkrunyuk in Malay * Called Enseluai in

Iban IBAN or Iban or Ibán may refer to: Banking * International Bank Account Number Ethnology * Iban culture * Iban language The Iban language () is spoken by the Iban, one of the Dayak ethnic groups who live in Brunei, the Indonesian provinc ...

Description

a large Rasbora, able to reach a total length of 15 cm (6 inches). Superficially resembles ''

Rasbora trilineata ''Rasbora trilineata'' is a species of ray-finned fish in the genus ''Rasbora''. Common names include scissortail rasbora and three-lined rasbora. It comes from Southeast Asia. Its length is up to 15 cm (6"). Aquarium In the wild, ''Rasbora tril ...

'', where it differ is the orange to red mark at each lobe of the

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

, just before the black mark on the fin lobes, and the larger adult size of ''R. caudimaculata.'' The

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

on specimens may also have a light orange mark.

Distribution

The geographical range of the species is debated as accounts of them from Southern Thailand and Cambodia are most likely misidentification. It is more likely the species is restricted to the southern tip of the

Peninsular Malaysia Peninsular Malaysia, historically known as Malaya and also known as West Malaysia or the Malaysian Peninsula, is the western part of Malaysia that comprises the southern part of the Malay Peninsula on Mainland Southeast Asia and the list of isla ...

, the

Greater Sunda Islands The Greater Sunda Islands (Indonesian language, Indonesian and Malay language, Malay: ''Kepulauan Sunda Besar'') are four tropical islands situated within the Indonesian Archipelago, in the Pacific Ocean. The islands, Borneo, Java, Sulawesi and S ...

and the whole of

Borneo Borneo () is the List of islands by area, third-largest island in the world, with an area of , and population of 23,053,723 (2020 national censuses). Situated at the geographic centre of Maritime Southeast Asia, it is one of the Greater Sunda ...

In Borneo, the species seem to be in abundant while in Peninsular Malaysia it is not a common species with very localized populations, possibly due to loss of habitat.

Habitat

It is an adaptable fast swimming species, able to live in fast flowing forest streams with a sandy or rocky bottom, or even sluggish blackwater habitats like peat swamp rivers. In most of these habitats, submerged plants or wood are used as hiding places from predators, young individuals are even documented near section of river where ''

Eusideroxylon zwageri ''Eusideroxylon'' is a genus of evergreen trees of the family Lauraceae. The genus is monotypic, and includes one accepted species, ''Eusideroxylon zwageri''. It is known colloquially in English as Bornean ironwood, billian, or ulin. It is nativ ...

'' trees grow. Some other species that live sympatricly with ''R. caudimaculata'' are '' R. borapetensis'', ''B. sealei'' and ''B. kuchingensis''. '' Channa lucius'' have been documented predating this species.

References

Greater scissortail Freshwater fish of Malaysia Freshwater fish of Indonesia Fish of the Mekong Basin Fish of Cambodia Fish of Singapore Fish of Thailand Taxa named by Walter Volz Fish described in 1903 {{Rasboras-stub