Balantiocheilos
Encyclopedia
Balantiocheilos is a small genus
of cyprinid
fish
. It includes two species
.
drainages in mainland Southeast Asia
; the original distribution of this species included the Chao Phraya River drainage from Bangkok
upriver to the lower Nan River
and in the Mekong from Vietnam
and the Great Lake (Tonle Sap
) to the lower Nam Ngum River. B. melanopterus occurs in the Mekong and Chao Phraya River basins, Malay Peninsula
, Sumatra
, and Borneo
.
lip bearing a large lobe that is deeply incised medially along its posterior edge and black along the distal margins of the dorsal, caudal, anal and pelvic fins. The posterior margin of the lower lip has often been described as forming a posteriorly opening pouch or pocket between the lip and the skin of the throat. B. ambusticauda can be differentiated from B. melanopterus by a shorter snout. Also, in B. ambusticauda the rictus (junction of the premaxilla and maxilla at the corner of the mouth) has posteriorly direct grooves that are curved instead of straight. Finally, B. ambusticauda has narrower black margins on the pelvic and anal fins (on the distal third or less instead of the distal half or more in B. melanopterus). B. ambusticauda also has some golden color as opposed to the silvery B. melanopterus. B. ambusticauda only reaches about 20 centimetres (8 in) TL
as opposed to 35 cm (14 in) TL in B. melanopterus.
by the IUCN Red List
. It has become rare or extinct
in many river basins of its native range. In Danau Sentarum (Borneo), fishermen already reported in 1993 and 1995 that the populations have decreased dramatically after 1975, for no clear reason. Fishermen mentioned overfishing for the aquarium-fish trade or forest fires in 1975 and the resulting pollution as possible causes. The species is apparently extirpated in the Batang Hari
basin (Sumatra
) and it seems that all individuals of B. melanopterus exported from Indonesia and Thailand by the aquarium-fish trade are captive bred.
B. ambusticauda is believed to have gone extinct even before it was scientifically described. Humphrey & Bain speculated the decline was due to excessive capture for the aquarium
fish trade, but this is unsubstantiated.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of cyprinid
Cyprinid
The family Cyprinidae, from the Ancient Greek kyprînos , consists of the carps, the true minnows, and their relatives . Commonly called the carp family or the minnow family, its members are also known as cyprinids...
fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
. It includes two species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
.
Species
- Balantiocheilos ambusticauda H. H. Ng & KottelatMaurice KottelatDr. Maurice Kottelat is a Swiss ichthyologist.In 1976 he entered the University of Neuchâtel where he obtained his diploma in 1987. In 1980 he went to Thailand where he began his field research on Southeast Asiatic and Indonesian fresh water fish species...
, 2007 (Burnt tail fish) - Balantiocheilos melanopterus (BleekerPieter BleekerPieter Bleeker was a Dutch medical doctor and ichthyologist, famous for his work on the fishes of East Asia – Atlas Ichthyologique des Orientales Neerlandaises – which was published 1862–1877....
, 1851) (Tricolor sharkminnow)
Distribution
The range of B. ambusticauda is listed as including the lower and middle Mekong and Chao Phraya RiverChao Phraya River
The Chao Phraya is a major river in Thailand, with its low alluvial plain forming the centre of the country. It runs through Bangkok, the capital city, and then empties into the Gulf of Thailand.-Etymology:...
drainages in mainland Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
; the original distribution of this species included the Chao Phraya River drainage from Bangkok
Bangkok
Bangkok is the capital and largest urban area city in Thailand. It is known in Thai as Krung Thep Maha Nakhon or simply Krung Thep , meaning "city of angels." The full name of Bangkok is Krung Thep Mahanakhon Amon Rattanakosin Mahintharayutthaya Mahadilok Phop Noppharat Ratchathani Burirom...
upriver to the lower Nan River
Nan River
The Nan River is a river in Thailand. It is one of the most important tributaries of the Chao Phraya River.-Geography:The Nan River originates in Nan Province. The provinces along the river after Nan Province are Uttaradit, Phitsanulok and Phichit. The Yom River joins the Nan River at Chum Saeng...
and in the Mekong from Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
and the Great Lake (Tonle Sap
Tonlé Sap
The Tonlé Sap is a combined lake and river system of major importance to Cambodia.The Tonlé Sap is the largest freshwater lake in South East Asia and is an ecological hot spot that was designated as a UNESCO biosphere in 1997....
) to the lower Nam Ngum River. B. melanopterus occurs in the Mekong and Chao Phraya River basins, Malay Peninsula
Malay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
, Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
, and Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
.
Description
Cyprinid fishes of the genus Balantiocheilos are easily distinguished from other members of the family by the presence of thick and fleshy lips, the lowerlip bearing a large lobe that is deeply incised medially along its posterior edge and black along the distal margins of the dorsal, caudal, anal and pelvic fins. The posterior margin of the lower lip has often been described as forming a posteriorly opening pouch or pocket between the lip and the skin of the throat. B. ambusticauda can be differentiated from B. melanopterus by a shorter snout. Also, in B. ambusticauda the rictus (junction of the premaxilla and maxilla at the corner of the mouth) has posteriorly direct grooves that are curved instead of straight. Finally, B. ambusticauda has narrower black margins on the pelvic and anal fins (on the distal third or less instead of the distal half or more in B. melanopterus). B. ambusticauda also has some golden color as opposed to the silvery B. melanopterus. B. ambusticauda only reaches about 20 centimetres (8 in) TL
Fish measurement
Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...
as opposed to 35 cm (14 in) TL in B. melanopterus.
Conservation
B. melanopterus is listed as an endangered speciesEndangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
by the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
. It has become rare or extinct
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
in many river basins of its native range. In Danau Sentarum (Borneo), fishermen already reported in 1993 and 1995 that the populations have decreased dramatically after 1975, for no clear reason. Fishermen mentioned overfishing for the aquarium-fish trade or forest fires in 1975 and the resulting pollution as possible causes. The species is apparently extirpated in the Batang Hari
Batang Hari River
The Batang Hari is the longest river in Sumatra, Indonesia. It originates in the Minangkabau highlands and flows to the east coast of Sumatra. The city of Jambi is located at the mouth of the river.-External links:...
basin (Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
) and it seems that all individuals of B. melanopterus exported from Indonesia and Thailand by the aquarium-fish trade are captive bred.
B. ambusticauda is believed to have gone extinct even before it was scientifically described. Humphrey & Bain speculated the decline was due to excessive capture for the aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
fish trade, but this is unsubstantiated.