Bala shark
Encyclopedia
The Bala shark, Balantiocheilos melanopterus, also known as the tricolor shark, silver shark, or shark minnow, is a fish
species
of the family
Cyprinid
ae, and is one of the two species in the genus
Balantiocheilos
. This species is not a true shark
, but is commonly called a "shark" because of its torpedo
-shaped body and large fins.It is endangered because the population decreased by 50% in the last 10 years.
basins, Malay Peninsula
, Sumatra
, and Borneo
.
, caudal, anal, and pelvic fins. They have big eyes to find and catch their prey. The Bala shark will grow to a maximum length of 12 inches but takes a long time to do so.
, but mostly on small crustacean
s, rotifer
s, and insect
s and their larva
e.
Bala sharks are popular aquarium
fish. These fish are generally peaceful and good companions to many other types of tropical fish
. The nickname "shark" is used because of their torpedo shaped bodies and long fins. They are not actual sharks. Bala sharks are widely available in most pet stores, but these fish may grow to a size too large for the home aquarium. Also the bala shark is a jumper fish and may injure itself on the lid of a tank.
They are a hardy fish that will tolerate temperature changes, pH
changes, and other factors to which other fish may be sensitive. The water pH
should be 6.0–8.0. The preferable water hardness for this species is soft to medium (5.0–12.0 dGH
). Water temperature should be kept between 22–28°C (72–82°F). The Bala shark prefers be kept in groups of two or more specimens (although they can survive alone). These fish require a covered aquarium as they are very skilled jumpers.
Very young Bala sharks are sometimes kept in small aquaria. However, given their adult size, schooling behavior, and swimming speed, the fish quickly grow to need much more room. Hobbyists continue to debate over acceptable minimum tank sizes, but generally recommend at least a 6 foot tank. FishBase
lists a minimum of 150 cm (5 ft). Many believe the fish is simply too large and too active to be kept in commercial aquaria at all; only enormous, custom-built tanks are acceptable, if any tank at all is. Indoor pond
s are also considered feasible housing options and may be better suited to the average aquarist. This fish's habitat is often destroyed, making these fish rare in the wild.
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.
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...
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...
of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
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...
ae, and is one of the two species in the genus
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...
Balantiocheilos
Balantiocheilos
Balantiocheilos is a small genus of cyprinid fish. It includes two species.- Species :*Balantiocheilos ambusticauda H. H. Ng & Kottelat, 2007 *Balantiocheilos melanopterus -Distribution:...
. This species is not a true shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
, but is commonly called a "shark" because of its torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
-shaped body and large fins.It is endangered because the population decreased by 50% in the last 10 years.
Distribution
The Bala shark occurs in the 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:...
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....
.
Appearance and anatomy
These fish have a silver body with black margins on their dorsalDorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
, caudal, anal, and pelvic fins. They have big eyes to find and catch their prey. The Bala shark will grow to a maximum length of 12 inches but takes a long time to do so.
Habitat and ecology
Bala sharks are found in midwater depths in large and medium-sized rivers and lakes. They feed on phytoplanktonPhytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
, but mostly on small crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, rotifer
Rotifer
The rotifers make up a phylum of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John Harris in 1696, and other forms were described by Anton van Leeuwenhoek in 1703...
s, and insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and their larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e.
In 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. These fish are generally peaceful and good companions to many other types of tropical fish
Tropical fish
Tropical fish include fish found in tropical environments around the world, including both freshwater and salt water species.Tropical fish are popular as aquarium fish, due to their often bright coloration...
. The nickname "shark" is used because of their torpedo shaped bodies and long fins. They are not actual sharks. Bala sharks are widely available in most pet stores, but these fish may grow to a size too large for the home aquarium. Also the bala shark is a jumper fish and may injure itself on the lid of a tank.
They are a hardy fish that will tolerate temperature changes, pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
changes, and other factors to which other fish may be sensitive. The water pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
should be 6.0–8.0. The preferable water hardness for this species is soft to medium (5.0–12.0 dGH
DGH
Degrees of general hardness is a unit of water hardness, specifically of general hardness.General hardness is a measure of the concentration of metal divalent ions such as calcium and magnesium per volume of water...
). Water temperature should be kept between 22–28°C (72–82°F). The Bala shark prefers be kept in groups of two or more specimens (although they can survive alone). These fish require a covered aquarium as they are very skilled jumpers.
FishBase
FishBase is a comprehensive database of information about fish species . It is the largest and most extensively accessed online database on adult finfish on the web...
lists a minimum of 150 cm (5 ft). Many believe the fish is simply too large and too active to be kept in commercial aquaria at all; only enormous, custom-built tanks are acceptable, if any tank at all is. Indoor pond
Pond
A pond is a body of standing water, either natural or man-made, that is usually smaller than a lake. A wide variety of man-made bodies of water are classified as ponds, including water gardens, water features and koi ponds; all designed for aesthetic ornamentation as landscape or architectural...
s are also considered feasible housing options and may be better suited to the average aquarist. This fish's habitat is often destroyed, making these fish rare in the wild.
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.