Rainbow shark
Epalzeorhynchos frenatum
An olive 'shark' with red fins, most often sold in its albino form; territorial toward lookalike bottom fish and best kept alone.
Key facts
- Body length
- 5.9 in without fins
- Minimum tank
- 76 gallons
- Group
- Alone is fine
- Temperament
- Aggressive
- Care level
- 3 / 5
- Lifespan
- 15+ years
- Diet
- Algae wafers, vegetables, sinking pellets, frozen bloodworm
- Origin
- Thailand, Laos and Cambodia
- Hardier than22%
- Bigger than73%
- Calmer than14%
Water: their range vs yours
Rainbow shark tank mates
- BettaGets along in shared water.Good mates
- AngelfishGets along in shared water.Good mates
- Blood parrot cichlidGets along in shared water.Good mates
- Common plecoGets along in shared water.Good mates
- Dwarf gouramiGets along in shared water.Good mates
- Leopard sailfin plecoGets along in shared water.Good mates
- SeverumGets along in shared water.Good mates
- Three spot gouramiGets along in shared water.Good mates
- Assassin snailGets along in shared water.Good mates
- Red swamp crayfishGets along in shared water.Good mates
- Redclaw crayfishGets along in shared water.Good mates
- Elephantnose fishGets along in shared water.Good mates
- Neon tetraRainbow shark attacks fish with a similar shape or colour: Neon tetra.Risky
- Harlequin rasboraRainbow shark attacks fish with a similar shape or colour: Harlequin rasbora.Risky
- Fancy guppyRainbow shark attacks fish with a similar shape or colour: Fancy guppy.Risky
- Panda corydorasRainbow shark (aggressive) will bully the peaceful Panda corydoras.Risky
- OtocinclusRainbow shark (aggressive) will bully the peaceful Otocinclus.Risky
- Cherry shrimpRainbow shark (aggressive) will bully the peaceful Cherry shrimp.Risky
- Iridescent sharkIridescent shark can eat Rainbow shark: prey body depth 3.3 cm ≤ mouth 32.5 cm.Avoid
- OscarOscar can eat Rainbow shark: prey body depth 3.3 cm ≤ mouth 12.3 cm.Avoid
- Red-tailed black sharkSharks fight lookalike sharks.Avoid
- Siamese algae eaterAttacks lookalike algae eaters.Avoid
- African clawed frogAfrican clawed frog should only be kept in a single-species tank.Avoid
- Marbled crayfishMarbled crayfish should only be kept in a single-species tank.Avoid
How we check
The numbers the tank model uses for rainbow sharks: water as ideal and tolerated ranges, bioload from adult mass, space, flow and how they act on other species.
- Standard length
- 15 cm (SL)
- Adult mass
- 55.50 g
- Bioload at 25 °C
- 12.80 BU
- Min. water
- 243 L net
- Min. footprint
- 120 × 45 cm per specimen
- Group
- 1+ (best 1)
- Swims in
- bottom, middle
- Flow
- moderate
- Body / fins
- fusiform, normal fins
- Diet type
- omnivore plant
- Fin nipper
- none
- Sensitive to
- nitrate
Sources: Seriously Fish: Epalzeorhynchos frenatum · FishBase: Epalzeorhynchos frenatum
Care notes
Rainbow sharks come from rivers and streams with sandy or rocky beds in Thailand, Laos and Cambodia. Albino and GloFish forms are common, and territorial behaviour grows stronger with age.
Keep one per tank in at least 55 gallons with a 4-foot footprint. It eats algae less eagerly than the Siamese algae eater and should not share a tank with other sharks or sucker-mouth algae eaters.
Questions
What size tank does a rainbow shark need?
At least 76 gallons (243 litres of water after decor). Adults reach about 5.9 inches without fins.
How many rainbow sharks should be kept together?
One is fine. They do not need company of their own kind.
What water do rainbow sharks need?
75–79 °F, pH 6.5–8 and 2–15 dGH. Rainbow sharks come from Thailand, Laos and Cambodia.
How long do rainbow sharks live?
15+ years with good care.
What fish can live with rainbow sharks?
Good tank mates include Betta, Angelfish, Blood parrot cichlid, Common pleco and Dwarf gourami. Each is checked both ways for size, fin nipping, temperament, territory and shared water.