The rainbow shark (''Epalzeorhynchos frenatum'') is a species of Southeast Asian freshwater fish from the family

Cyprinidae Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest verte ...

. It is also known as the ruby shark, red-fin shark, red-finned shark, rainbow sharkminnow, green fringelip labeo, whitefin shark and whitetail sharkminnow.Red-fin Shark, Rainbow Shark, Ruby Shark (''Epalzeorhynchus frenatus''), Mongabay.com, 2006
retrieved on August 17, 2007Rainbow Shark (''Epalzeorhynchos frenatum''), AquariumLife.net (undated)
retrieved on August 17, 2007 It is a popular, semi-aggressive aquarium fish. Unlike true sharks, which belong to the Chondrichthyes ("cartilagenous fishes") lineage, the rainbow shark is an

actinopterygii Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

an ("ray-finned fish").

Distribution and habitat

Rainbow sharks are native to the basins of Mekong, Chao Phraya, Xe Bangfai and Maeklong in Indochina. They live in water with sandy substrates, near the river bottom. This species feeds on algae and plankton, and seasonally migrates into flooded areas, then recedes back to the rivers as the floods dry up.

Description

The rainbow shark has an elongated black, dark blue or bright blue body. The snout is pointed. The abdominal area is flat. The fins possess red to orange-red coloration. The linear area from the gill cover, the eye, and the mouth has a characteristic brief stripe. Compared to females, male rainbow sharks have thinner bodies with black lines along the tailfins. Males also have brighter coloration. They can grow up to about long.

Variants

The albino red-fin shark or albino rainbow sharkminnow is a variety of rainbow shark with a white body and red/orange fins.Fenner, Bob. The Rainbow, Redfin and Albino Minnow Sharks, Epalzeorhynchos munense and E. frenatum, The Conscientious Aquarist, WetWebMedia.com (undated)
retrieved on August 17, 2007 It closely resembles "normal" rainbow sharks in temperament and appearance, thus they share the same common names in the aquarium industry.
retrieved on August 17, 2007 These have sometimes been referred to as '' E. munense'', but that is a separate species that rarely enters the aquarium trade. The rainbow shark is also one of the types of genetically modified, fluorescent fish known as GloFish. Whitefin Rainbow

Another variant that exists is a rarer form, often referred to as the “ghost sharkminnow”. Its appearance is otherwise identical to the typical rainbow shark, however its fins are white, and almost transparent

In the aquarium

Behavior

Rainbow sharks are tank-bottom and aquarium-surface cleaners. Being bottom- and mid-level dwellers, they consume leftover fish food, but also eat the algae growing off surfaces. They are known to be peaceful with their own kind in the wild but have been known to be aggressive with one another if kept together in a tank. Threat displays and fighting are likely to occur. This fighting behavior involves head-and-tail butting, and also biting.. A large rainbow shark will continuously chase a smaller one until the smaller one dies, or chase other fish out of its territory, especially in confined environments like aquaria. It may also increase the risk of the fish jumping out of its tank. This makes breeding difficult. The provision of hiding places and hollowed decors such as plants or artificial cave-like and tunnel-like aquatic ornaments minimize this typical behavior. Due to this behavioral characteristic among its own kind, rainbow sharks are not recommendable to the new aquarist. Keeping them with relatives, such as red-tailed sharks,

bala shark The bala shark, ''Balantiocheilos melanopterus'', also known as the tricolor shark, tricolor sharkminnow, silver shark, or shark minnow, is a fish of the family Cyprinidae, and is one of the two species in the genus ''Balantiocheilos''. This spec ...

s and black sharks should be avoided, as they will chase and attack them as well.

Tank requirements

An adult rainbow shark thrives in a minimum of 55 gallons of water, with an aquarium length of 48 inches, at the neutral pH range (6 to 8 pH), with temperatures between , and water hardness maintained at 5 to 11 dH. They must have this much space, as they frequently swim around quickly and will terrorize other fish in any tank under this size.

Compatibility

Rainbow sharks are compatible with barbs and rainbowfish, which are upper- and middle-tank dwellers. They can also live with

danio ''Danio'' is a genus of small freshwater fish in the family Cyprinidae found in South and Southeast Asia, commonly kept in aquaria. They are generally characterised by a pattern of horizontal stripes, rows of spots or vertical bars. Some species ...

loaches Loaches are fish of the superfamily Cobitoidea. They are freshwater, benthic (bottom-dwelling) fish found in rivers and creeks throughout Eurasia and northern Africa. Loaches are among the most diverse groups of fish; the 1249 known species of ...

, plecos, rasboras, and gouramis. They can be housed with some species of larger freshwater shrimp although any fry or eggs might get eaten by the shark. They are not compatible with smaller, more timid fish in the tank, as the sharks may terrorize them by chasing them from their territory.Rainbow Shark Information, TimsTropicals.com, 2007
retrieved on August 17, 2007

Diet

Rainbow sharks are picky herbivorous and omnivorous eaters but are primarily consumers of

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

in the form of flakes. They also eat live foods, such as insect larvae,

tubifex worms ''Tubifex'' is a cosmopolitan genus of tubificid annelids that inhabits the sediments of lakes, rivers and occasionally sewer lines. At least 13 species of ''Tubifex'' have been identified, with the exact number not certain, as the species are ...

, periphyton, crustaceans,

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Ph ...

, zooplankton and aquatic insects. Diet also include lettuce and

spinach Spinach (''Spinacia oleracea'') is a leafy green flowering plant native to central and western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common edible vegetable consumed either f ...

. They will also eat frozen bloodworms and brine shrimp.

Breeding

No actual breed sequence has been documented in an aquarium setting. Although known to be egg-layers, reproduction of rainbow sharks is difficult in an aquarium setting. Large numbers are bred in southeast Asian commercial farms.SeriouslyFish:
Epalzeorhynchos frenatum.
' Retrieved 30 July 2014.

References

External links

* {{DEFAULTSORT:shark, rainbow

rainbow shark The rainbow shark (''Epalzeorhynchos frenatum'') is a species of Southeast Asian freshwater fish from the family Cyprinidae. It is also known as the ruby shark, red-fin shark, red-finned shark, rainbow sharkminnow, green fringelip labeo, whitefi ...

Taxa named by Henry Weed Fowler