Aquariumshark & minnow · freshwater
Red-Tail Shark: adult size, tank size & tankmates
The Red-Tail Shark (Epalzeorhynchos bicolor) grows to about 5.9 in (12.5 cm SL). It needs a tank at least 48 inches long and about 64 gallons. It doesn't need a group of its own kind, at 68–79°F.
How big it really gets
Drawn to scale against common tank lengths. Green bars meet the minimum tank length from our sources.
Outgrows most home tanks. Sold as a flashy 2-inch fish; becomes territorial and violently attacks conspecifics and bottom-dwellers in small tanks.
Will it fit your tank?
Quick facts
- Adult size
- 5.9 in (12.5 cm SL)
- Minimum tank
- 48 inches long and about 64 gallons
- Temperature
- 68–79°F
- pH
- 6–8
- Hardness
- 2–15 dGH
- Group size
- 1 (solitary or pair)
- With other fish
- semi-aggressive
- With its own kind
- aggressive
- Swims
- bottom of the tank
- Diet
- omnivore
- Care level
- intermediate
- Lifespan
- 15 years
Watch for: eats shrimp · jumps, so keep a lid
Red-Tail Shark tankmates
Checked with the same rules as our tank builder: temperature overlap, pH and hardness, predation and mouth size, fin-nipping and temperament. Tank size is left out here; check it in the builder.
Good tankmates
- Dwarf GouramiNeeds careAdult ~4.2 in · 72–81°F
- Pearl GouramiAdult ~5.7 in · 75–86°F
- BettaNeeds careAdult ~3.3 in · 72–86°F
- KribensisAdult ~4.7 in · 75–81°F
- AngelfishNeeds careAdult ~7.1 in · 75–86°F
- Kuhli LoachAdult ~4.7 in · 70–79°F
- Bristlenose PlecoAdult ~5.9 in · 70–79°F
- Nerite SnailAdult ~1 in · 72–78°F
- Tiger BarbNeeds careAdult ~2.8 in · 68–79°F
- SwordtailNeeds careAdult ~6.6 in · 61–82°F
Use caution
- Neon TetraRed-Tail Shark grows 4× longer than Neon Tetra and may treat it as food.
- Cardinal TetraRed-Tail Shark can bully smaller, peaceful Cardinal Tetra.
- Harlequin RasboraRed-Tail Shark can bully smaller, peaceful Harlequin Rasbora.
- Ember TetraRed-Tail Shark grows 6× longer than Ember Tetra and may treat it as food.
- Chili RasboraRed-Tail Shark grows 6× longer than Chili Rasbora and may treat it as food.
- Celestial Pearl DanioRed-Tail Shark grows 6× longer than Celestial Pearl Danio and may treat it as food.
- Cherry BarbRed-Tail Shark can bully smaller, peaceful Cherry Barb.
- Rummy-nose TetraRed-Tail Shark can bully smaller, peaceful Rummy-nose Tetra.
Avoid
- German Blue RamNeeds careRed-Tail Shark (68–79°F) and German Blue Ram (81–86°F) need different temperatures.
- Cherry ShrimpRed-Tail Shark will eat Cherry Shrimp.
- Amano ShrimpRed-Tail Shark will eat Amano Shrimp.
- Boesemani RainbowfishRed-Tail Shark (68–79°F) and Boesemani Rainbowfish (81–86°F) need different temperatures.
- Bamboo ShrimpRed-Tail Shark will eat Bamboo Shrimp.
- Crystal Red ShrimpRed-Tail Shark will eat Crystal Red Shrimp.
- Ghost ShrimpRed-Tail Shark will eat Ghost Shrimp.
- Iridescent SharkOutgrows tanksIridescent Shark eats small fish, and Red-Tail Shark only grows to about 5.9 in.
All 105 species we checked against the Red-Tail Shark
| Species | Verdict | Why |
|---|---|---|
| Angelfish | Compatible | No conflicts found |
| Assassin Snail | Compatible | No conflicts found |
| Bala Shark | Compatible | No conflicts found |
| Betta | Compatible | No conflicts found |
| Black Skirt Tetra | Compatible | No conflicts found |
| Blood Parrot Cichlid | Compatible | No conflicts found |
| Bristlenose Pleco | Compatible | No conflicts found |
| Buenos Aires Tetra | Compatible | No conflicts found |
| Chinese Algae Eater | Compatible | No conflicts found |
| Clown Loach | Compatible | No conflicts found |
| Clown Pleco | Compatible | No conflicts found |
| Common / Comet Goldfish | Compatible | No conflicts found |
| Common Pleco | Compatible | No conflicts found |
| Convict Cichlid | Compatible | No conflicts found |
| Denison Barb | Compatible | No conflicts found |
| Dwarf Gourami | Compatible | No conflicts found |
| Electric Blue Acara | Compatible | No conflicts found |
| Electric Yellow Lab | Compatible | No conflicts found |
| Fancy Goldfish | Compatible | No conflicts found |
| Firemouth Cichlid | Compatible | No conflicts found |
| Japanese Trapdoor Snail | Compatible | No conflicts found |
| Kissing Gourami | Compatible | No conflicts found |
| Kribensis | Compatible | No conflicts found |
| Kuhli Loach | Compatible | No conflicts found |
| Malaysian Trumpet Snail | Compatible | No conflicts found |
| Moonlight Gourami | Compatible | No conflicts found |
| Nerite Snail | Compatible | No conflicts found |
| Oscar | Compatible | No conflicts found |
| Paradise Fish | Compatible | No conflicts found |
| Pearl Gourami | Compatible | No conflicts found |
| Pictus Catfish | Compatible | No conflicts found |
| Rainbow Shark | Compatible | No conflicts found |
| Ramshorn Snail | Compatible | No conflicts found |
| Rosy Barb | Compatible | No conflicts found |
| Scissortail Rasbora | Compatible | No conflicts found |
| Serpae Tetra | Compatible | No conflicts found |
| Siamese Algae Eater | Compatible | No conflicts found |
| Swordtail | Compatible | No conflicts found |
| Three-spot Gourami | Compatible | No conflicts found |
| Tiger Barb | Compatible | No conflicts found |
| Tinfoil Barb | Compatible | No conflicts found |
| Upside-down Catfish | Compatible | No conflicts found |
| Weather Loach | Compatible | No conflicts found |
| Yoyo Loach | Compatible | No conflicts found |
| African Dwarf Frog | Caution | Red-Tail Shark grows 4× longer than African Dwarf Frog and may treat it as food.; Red-Tail Shark can bully smaller, peaceful African Dwarf Frog. |
| Black Neon Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Black Neon Tetra. |
| Bleeding Heart Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Bleeding Heart Tetra. |
| Bolivian Ram | Caution | Red-Tail Shark can bully smaller, peaceful Bolivian Ram. |
| Bronze Cory | Caution | Red-Tail Shark can bully smaller, peaceful Bronze Cory. |
| Bumblebee Goby | Caution | Red-Tail Shark can bully smaller, peaceful Bumblebee Goby. |
| Cardinal Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Cardinal Tetra. |
| Celestial Pearl Danio | Caution | Red-Tail Shark grows 6× longer than Celestial Pearl Danio and may treat it as food.; Red-Tail Shark can bully smaller, peaceful Celestial Pearl Danio. |
| Cherry Barb | Caution | Red-Tail Shark can bully smaller, peaceful Cherry Barb. |
| Chili Rasbora | Caution | Red-Tail Shark grows 6× longer than Chili Rasbora and may treat it as food.; Red-Tail Shark can bully smaller, peaceful Chili Rasbora. |
| Clown Killifish | Caution | Red-Tail Shark can bully smaller, peaceful Clown Killifish. |
| Cockatoo Dwarf Cichlid | Caution | Red-Tail Shark can bully smaller, peaceful Cockatoo Dwarf Cichlid. |
| Congo Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Congo Tetra. |
| Diamond Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Diamond Tetra. |
| Discus | Caution | Red-Tail Shark and Discus only share 79–79°F. That's a tight window. |
| Dwarf Neon Rainbowfish | Caution | Red-Tail Shark can bully smaller, peaceful Dwarf Neon Rainbowfish. |
| Ember Tetra | Caution | Red-Tail Shark grows 6× longer than Ember Tetra and may treat it as food.; Red-Tail Shark can bully smaller, peaceful Ember Tetra. |
| Endler's Livebearer | Caution | Red-Tail Shark grows 5× longer than Endler's Livebearer and may treat it as food.; Red-Tail Shark can bully smaller, peaceful Endler's Livebearer. |
| Forktail Blue-eye | Caution | Red-Tail Shark can bully smaller, peaceful Forktail Blue-eye. |
| Giant Danio | Caution | Red-Tail Shark can bully smaller, peaceful Giant Danio. |
| Glass Catfish | Caution | Red-Tail Shark can bully smaller, peaceful Glass Catfish. |
| Glowlight Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Glowlight Tetra. |
| Gold Barb | Caution | Red-Tail Shark can bully smaller, peaceful Gold Barb. |
| Guppy | Caution | Red-Tail Shark can bully smaller, peaceful Guppy. |
| Harlequin Rasbora | Caution | Red-Tail Shark can bully smaller, peaceful Harlequin Rasbora. |
| Head-and-tail-light Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Head-and-tail-light Tetra. |
| Hillstream Loach | Caution | Red-Tail Shark can bully smaller, peaceful Hillstream Loach. |
| Honey Gourami | Caution | Red-Tail Shark can bully smaller, peaceful Honey Gourami. |
| Julii Cory | Caution | Red-Tail Shark can bully smaller, peaceful Julii Cory. |
| Lambchop Rasbora | Caution | Red-Tail Shark grows 4× longer than Lambchop Rasbora and may treat it as food.; Red-Tail Shark can bully smaller, peaceful Lambchop Rasbora. |
| Lemon Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Lemon Tetra. |
| Marbled Hatchetfish | Caution | Red-Tail Shark can bully smaller, peaceful Marbled Hatchetfish. |
| Molly | Caution | Red-Tail Shark can bully smaller, peaceful Molly. |
| Mystery Snail | Caution | Red-Tail Shark (pH 6–8) and Mystery Snail (pH unknown) prefer different pH.; Red-Tail Shark (2–15 dGH) and Mystery Snail (unknown dGH) prefer different water hardness. |
| Neon Tetra | Caution | Red-Tail Shark grows 4× longer than Neon Tetra and may treat it as food.; Red-Tail Shark can bully smaller, peaceful Neon Tetra. |
| Odessa Barb | Caution | Red-Tail Shark can bully smaller, peaceful Odessa Barb. |
| Otocinclus | Caution | Red-Tail Shark can bully smaller, peaceful Otocinclus. |
| Panda Cory | Caution | Red-Tail Shark can bully smaller, peaceful Panda Cory. |
| Pea Puffer | Caution | Red-Tail Shark grows 4× longer than Pea Puffer and may treat it as food. |
| Pearl Danio | Caution | Red-Tail Shark can bully smaller, peaceful Pearl Danio. |
| Penguin Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Penguin Tetra. |
| Peppered Cory | Caution | Red-Tail Shark can bully smaller, peaceful Peppered Cory. |
| Platy | Caution | Red-Tail Shark can bully smaller, peaceful Platy. |
| Pristella Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Pristella Tetra. |
| Pygmy Cory | Caution | Red-Tail Shark grows 4× longer than Pygmy Cory and may treat it as food.; Red-Tail Shark can bully smaller, peaceful Pygmy Cory. |
| Rummy-nose Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Rummy-nose Tetra. |
| Silver Hatchetfish | Caution | Red-Tail Shark can bully smaller, peaceful Silver Hatchetfish. |
| Silver Tip Tetra | Caution | Red-Tail Shark can bully smaller, peaceful Silver Tip Tetra. |
| Sparkling Gourami | Caution | Red-Tail Shark can bully smaller, peaceful Sparkling Gourami. |
| Sterbai Cory | Caution | Red-Tail Shark can bully smaller, peaceful Sterbai Cory. |
| Variatus Platy | Caution | Red-Tail Shark can bully smaller, peaceful Variatus Platy. |
| White Cloud Mountain Minnow | Caution | Red-Tail Shark can bully smaller, peaceful White Cloud Mountain Minnow. |
| Zebra Danio | Caution | Red-Tail Shark can bully smaller, peaceful Zebra Danio. |
| Amano Shrimp | Avoid | Red-Tail Shark will eat Amano Shrimp. |
| Bamboo Shrimp | Avoid | Red-Tail Shark will eat Bamboo Shrimp. |
| Boesemani Rainbowfish | Avoid | Red-Tail Shark (68–79°F) and Boesemani Rainbowfish (81–86°F) need different temperatures. |
| Cherry Shrimp | Avoid | Red-Tail Shark will eat Cherry Shrimp. |
| Crystal Red Shrimp | Avoid | Red-Tail Shark will eat Crystal Red Shrimp. |
| German Blue Ram | Avoid | Red-Tail Shark (68–79°F) and German Blue Ram (81–86°F) need different temperatures.; Red-Tail Shark can bully smaller, peaceful German Blue Ram. |
| Ghost Shrimp | Avoid | Red-Tail Shark will eat Ghost Shrimp. |
| Iridescent Shark | Avoid | Iridescent Shark eats small fish, and Red-Tail Shark only grows to about 5.9 in. |
Care notes
Needs: Requires complex hardscaping with multiple visual barriers; relentless chaser that stresses timid bottom tankmates
Group: Must be housed strictly singly; hyper-aggressive and lethal toward conspecifics and similar morphotypes
Temperament: semi-aggressive toward other fish, aggressive toward its own kind. Lives in the bottom of the tank.
Common questions
How big does a Red-Tail Shark get?
About 5.9 inches (12.5 cm SL) as an adult, according to seriouslyfish.com.
What size tank does a Red-Tail Shark need?
At least 48 inches long and about 64 gallons. The smallest standard tank that meets that is a 75 gallon.
How many Red-Tail Sharks should be kept together?
It can be kept on its own. Must be housed strictly singly; hyper-aggressive and lethal toward conspecifics and similar morphotypes
What fish can live with a Red-Tail Shark?
Species that passed every check include Dwarf Gourami, Pearl Gourami, Betta, Kribensis, Angelfish, Kuhli Loach.
Gear for a Red-Tail Shark setup
TankSmallest standard tank that meets its minimum: 75 gallon (48 in long).Find on Amazon →HeaterAbout 2 × 200 W for 75 gallons, holding 68–79°F.Find on Amazon →LidIt jumps. A full lid keeps it in the tank.Find on Amazon →FoodSinking food reaches the bottom before tankmates grab it.Find on Amazon →Test kitCheck ammonia, nitrite and pH. Cycle the tank before adding fish.Find on Amazon →
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Related guides
Sources
Values come from these pages, in our own words. Status: verified. Last reviewed 2026-10-12.
- seriouslyfish.com /species/epalzeorhynchos-bicolor
- fishbase.se /summary/Epalzeorhynchos-bicolor.html