Aquariumkillifish · freshwater
Clown Killifish: adult size, tank size & tankmates
The Clown Killifish (Epiplatys annulatus) grows to about 1.6 in (4 cm TL). It needs a tank at least 18 inches long and about 11 gallons. Keep at least 8 together, 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.
Will it fit your tank?
Quick facts
- Adult size
- 1.6 in (4 cm TL)
- Minimum tank
- 18 inches long and about 11 gallons
- Temperature
- 68–79°F
- pH
- 4–7
- Hardness
- 1–8 dGH
- Group size
- 8+
- With other fish
- peaceful
- With its own kind
- peaceful
- Swims
- top of the tank
- Diet
- carnivore
- Care level
- intermediate
- Lifespan
- not stated in sources
Watch for: may eat baby shrimp · jumps, so keep a lid
Clown Killifish 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
- Neon TetraAdult ~1.4 in · 70–77°F
- Cardinal TetraAdult ~1.7 in · 73–84°F
- Harlequin RasboraAdult ~2.1 in · 70–82°F
- Ember TetraAdult ~0.9 in · 68–82°F
- Chili RasboraAdult ~0.9 in · 68–82°F
- Celestial Pearl DanioAdult ~1 in · 68–79°F
- Cherry BarbAdult ~2.4 in · 68–81°F
- Rummy-nose TetraAdult ~2.4 in · 73–79°F
- Black Neon TetraAdult ~1.7 in · 73–82°F
- Glowlight TetraAdult ~1.9 in · 75–82°F
Use caution
- PlatyClown Killifish (1–8 dGH) and Platy (10–30 dGH) prefer different water hardness.
- Endler's LivebearerNeeds careClown Killifish (1–8 dGH) and Endler's Livebearer (15–35 dGH) prefer different water hardness.
- Dwarf GouramiNeeds careDwarf Gourami can bully smaller, peaceful Clown Killifish.
- BettaNeeds careBetta can bully smaller, peaceful Clown Killifish.
- Cherry ShrimpClown Killifish may eat baby Cherry Shrimp. Adults are usually safe, but expect fewer shrimplets.
- Amano ShrimpClown Killifish may eat baby Amano Shrimp. Adults are usually safe, but expect fewer shrimplets.
- Nerite SnailClown Killifish (pH 4–7) and Nerite Snail (pH 8–8.4) prefer different pH.
- Mystery SnailClown Killifish (pH 4–7) and Mystery Snail (pH unknown) prefer different pH.
Avoid
- German Blue RamNeeds careClown Killifish (68–79°F) and German Blue Ram (81–86°F) need different temperatures.
- AngelfishNeeds careAngelfish eats small fish, and Clown Killifish only grows to about 1.6 in.
- Boesemani RainbowfishClown Killifish (68–79°F) and Boesemani Rainbowfish (81–86°F) need different temperatures.
- Bala SharkOutgrows tanksBala Shark eats small fish, and Clown Killifish only grows to about 1.6 in.
- Blood Parrot CichlidOutgrows tanksBlood Parrot Cichlid eats small fish, and Clown Killifish only grows to about 1.6 in.
- Chinese Algae EaterOutgrows tanksChinese Algae Eater grows 8× longer than Clown Killifish and may treat it as food.
- Common / Comet GoldfishOutgrows tanksCommon / Comet Goldfish eats small fish, and Clown Killifish only grows to about 1.6 in.
- Convict CichlidNeeds careConvict Cichlid eats small fish, and Clown Killifish only grows to about 1.6 in.
All 105 species we checked against the Clown Killifish
| Species | Verdict | Why |
|---|---|---|
| African Dwarf Frog | Compatible | No conflicts found |
| Black Neon Tetra | Compatible | No conflicts found |
| Bleeding Heart Tetra | Compatible | No conflicts found |
| Bolivian Ram | Compatible | No conflicts found |
| Bristlenose Pleco | Compatible | No conflicts found |
| Bronze Cory | Compatible | No conflicts found |
| Bumblebee Goby | Compatible | No conflicts found |
| Cardinal Tetra | Compatible | No conflicts found |
| Celestial Pearl Danio | Compatible | No conflicts found |
| Cherry Barb | Compatible | No conflicts found |
| Chili Rasbora | Compatible | No conflicts found |
| Clown Loach | Compatible | No conflicts found |
| Clown Pleco | Compatible | No conflicts found |
| Cockatoo Dwarf Cichlid | Compatible | No conflicts found |
| Congo Tetra | Compatible | No conflicts found |
| Denison Barb | Compatible | No conflicts found |
| Diamond Tetra | Compatible | No conflicts found |
| Dwarf Neon Rainbowfish | Compatible | No conflicts found |
| Ember Tetra | Compatible | No conflicts found |
| Giant Danio | Compatible | No conflicts found |
| Glass Catfish | Compatible | No conflicts found |
| Glowlight Tetra | Compatible | No conflicts found |
| Gold Barb | Compatible | No conflicts found |
| Guppy | Compatible | No conflicts found |
| Harlequin Rasbora | Compatible | No conflicts found |
| Head-and-tail-light Tetra | Compatible | No conflicts found |
| Hillstream Loach | Compatible | No conflicts found |
| Honey Gourami | Compatible | No conflicts found |
| Japanese Trapdoor Snail | Compatible | No conflicts found |
| Julii Cory | Compatible | No conflicts found |
| Kribensis | Compatible | No conflicts found |
| Kuhli Loach | Compatible | No conflicts found |
| Lambchop Rasbora | Compatible | No conflicts found |
| Lemon Tetra | Compatible | No conflicts found |
| Malaysian Trumpet Snail | Compatible | No conflicts found |
| Marbled Hatchetfish | Compatible | No conflicts found |
| Moonlight Gourami | Compatible | No conflicts found |
| Neon Tetra | Compatible | No conflicts found |
| Odessa Barb | Compatible | No conflicts found |
| Otocinclus | Compatible | No conflicts found |
| Panda Cory | Compatible | No conflicts found |
| Pea Puffer | Compatible | No conflicts found |
| Pearl Danio | Compatible | No conflicts found |
| Pearl Gourami | Compatible | No conflicts found |
| Penguin Tetra | Compatible | No conflicts found |
| Peppered Cory | Compatible | No conflicts found |
| Pristella Tetra | Compatible | No conflicts found |
| Pygmy Cory | Compatible | No conflicts found |
| Ramshorn Snail | Compatible | No conflicts found |
| Rosy Barb | Compatible | No conflicts found |
| Rummy-nose Tetra | Compatible | No conflicts found |
| Scissortail Rasbora | Compatible | No conflicts found |
| Serpae Tetra | Compatible | No conflicts found |
| Siamese Algae Eater | Compatible | No conflicts found |
| Silver Hatchetfish | Compatible | No conflicts found |
| Silver Tip Tetra | Compatible | No conflicts found |
| Sparkling Gourami | Compatible | No conflicts found |
| Sterbai Cory | Compatible | No conflicts found |
| Upside-down Catfish | Compatible | No conflicts found |
| Weather Loach | Compatible | No conflicts found |
| White Cloud Mountain Minnow | Compatible | No conflicts found |
| Zebra Danio | Compatible | No conflicts found |
| Amano Shrimp | Caution | Clown Killifish may eat baby Amano Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Assassin Snail | Caution | Clown Killifish (pH 4–7) and Assassin Snail (pH 7.5–8) prefer different pH. |
| Bamboo Shrimp | Caution | Clown Killifish may eat baby Bamboo Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Betta | Caution | Betta can bully smaller, peaceful Clown Killifish. |
| Black Skirt Tetra | Caution | Black Skirt Tetra can bully smaller, peaceful Clown Killifish. |
| Buenos Aires Tetra | Caution | Buenos Aires Tetra can bully smaller, peaceful Clown Killifish. |
| Cherry Shrimp | Caution | Clown Killifish may eat baby Cherry Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Common Pleco | Caution | Clown Killifish (1–8 dGH) and Common Pleco (10–20 dGH) prefer different water hardness. |
| Crystal Red Shrimp | Caution | Clown Killifish may eat baby Crystal Red Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Discus | Caution | Clown Killifish and Discus only share 79–79°F. That's a tight window. |
| Dwarf Gourami | Caution | Dwarf Gourami can bully smaller, peaceful Clown Killifish. |
| Electric Yellow Lab | Caution | Electric Yellow Lab can bully smaller, peaceful Clown Killifish.; Clown Killifish (pH 4–7) and Electric Yellow Lab (pH 7.7–8.6) prefer different pH. |
| Endler's Livebearer | Caution | Clown Killifish (1–8 dGH) and Endler's Livebearer (15–35 dGH) prefer different water hardness. |
| Forktail Blue-eye | Caution | Clown Killifish (1–8 dGH) and Forktail Blue-eye (15–30 dGH) prefer different water hardness. |
| Ghost Shrimp | Caution | Clown Killifish may eat baby Ghost Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Kissing Gourami | Caution | Kissing Gourami grows 8× longer than Clown Killifish and may treat it as food.; Kissing Gourami can bully smaller, peaceful Clown Killifish. |
| Molly | Caution | Clown Killifish (1–8 dGH) and Molly (15–30 dGH) prefer different water hardness. |
| Mystery Snail | Caution | Clown Killifish (pH 4–7) and Mystery Snail (pH unknown) prefer different pH.; Clown Killifish (1–8 dGH) and Mystery Snail (unknown dGH) prefer different water hardness. |
| Nerite Snail | Caution | Clown Killifish (pH 4–7) and Nerite Snail (pH 8–8.4) prefer different pH. |
| Paradise Fish | Caution | Paradise Fish can bully smaller, peaceful Clown Killifish. |
| Platy | Caution | Clown Killifish (1–8 dGH) and Platy (10–30 dGH) prefer different water hardness. |
| Rainbow Shark | Caution | Rainbow Shark grows 5× longer than Clown Killifish and may treat it as food.; Rainbow Shark can bully smaller, peaceful Clown Killifish. |
| Red-Tail Shark | Caution | Red-Tail Shark can bully smaller, peaceful Clown Killifish. |
| Swordtail | Caution | Clown Killifish (1–8 dGH) and Swordtail (10–25 dGH) prefer different water hardness. |
| Three-spot Gourami | Caution | Three-spot Gourami grows 5× longer than Clown Killifish and may treat it as food.; Three-spot Gourami can bully smaller, peaceful Clown Killifish. |
| Tiger Barb | Caution | Tiger Barb can bully smaller, peaceful Clown Killifish. |
| Variatus Platy | Caution | Clown Killifish (1–8 dGH) and Variatus Platy (14–30 dGH) prefer different water hardness. |
| Yoyo Loach | Caution | Yoyo Loach grows 5× longer than Clown Killifish and may treat it as food.; Yoyo Loach can bully smaller, peaceful Clown Killifish. |
| Angelfish | Avoid | Angelfish eats small fish, and Clown Killifish only grows to about 1.6 in. |
| Bala Shark | Avoid | Bala Shark eats small fish, and Clown Killifish only grows to about 1.6 in. |
| Blood Parrot Cichlid | Avoid | Blood Parrot Cichlid eats small fish, and Clown Killifish only grows to about 1.6 in. |
| Boesemani Rainbowfish | Avoid | Clown Killifish (68–79°F) and Boesemani Rainbowfish (81–86°F) need different temperatures.; Clown Killifish (1–8 dGH) and Boesemani Rainbowfish (9–20 dGH) prefer different water hardness. |
| Chinese Algae Eater | Avoid | Chinese Algae Eater grows 8× longer than Clown Killifish and may treat it as food.; Chinese Algae Eater is aggressive toward tankmates. Clown Killifish is peaceful. |
| Common / Comet Goldfish | Avoid | Common / Comet Goldfish eats small fish, and Clown Killifish only grows to about 1.6 in. |
| Convict Cichlid | Avoid | Convict Cichlid eats small fish, and Clown Killifish only grows to about 1.6 in.; Convict Cichlid is aggressive toward tankmates. Clown Killifish is peaceful. |
| Electric Blue Acara | Avoid | Electric Blue Acara eats small fish, and Clown Killifish only grows to about 1.6 in. |
| Fancy Goldfish | Avoid | Fancy Goldfish eats small fish, and Clown Killifish only grows to about 1.6 in. |
| Firemouth Cichlid | Avoid | Firemouth Cichlid eats small fish, and Clown Killifish only grows to about 1.6 in. |
| German Blue Ram | Avoid | Clown Killifish (68–79°F) and German Blue Ram (81–86°F) need different temperatures. |
| Iridescent Shark | Avoid | Iridescent Shark eats small fish, and Clown Killifish only grows to about 1.6 in. |
| Oscar | Avoid | Oscar eats small fish, and Clown Killifish only grows to about 1.6 in. |
| Pictus Catfish | Avoid | Pictus Catfish eats small fish, and Clown Killifish only grows to about 1.6 in. |
| Tinfoil Barb | Avoid | Tinfoil Barb eats small fish, and Clown Killifish only grows to about 1.6 in. |
Care notes
Needs: Tight lid with gaps covered (jumps); surface dweller, slow water; small fish with specialised needs, not an ideal community fish; daily small live or frozen foods
Group: SF: relatively gregarious, buy at least 8-10; males spar for dominance but rarely harm one another; Co-Op suggests 1 male to 2-3 females
Temperament: peaceful toward other fish, peaceful toward its own kind. Lives in the top of the tank.
Common questions
How big does a Clown Killifish get?
About 1.6 inches (4 cm TL) as an adult, according to seriouslyfish.com.
What size tank does a Clown Killifish need?
At least 18 inches long and about 11 gallons. The smallest standard tank that meets that is a 20 gallon long.
How many Clown Killifishs should be kept together?
At least 8. SF: relatively gregarious, buy at least 8-10; males spar for dominance but rarely harm one another; Co-Op suggests 1 male to 2-3 females
What fish can live with a Clown Killifish?
Species that passed every check include Neon Tetra, Cardinal Tetra, Harlequin Rasbora, Ember Tetra, Chili Rasbora, Celestial Pearl Danio.
Gear for a Clown Killifish setup
TankSmallest standard tank that meets its minimum: 20 gallon long (30 in long).Find on Amazon →HeaterAbout 100 W for 20 gallons, holding 68–79°F.Find on Amazon →LidIt jumps. A full lid keeps it in the tank.Find on Amazon →FoodMeaty frozen foods suit its diet.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: researched from source pages. Last reviewed 2026-10-12.
- seriouslyfish.com /species/epiplatys-annulatus/
- fishbase.se /summary/Epiplatys-annulatus.html
- aquariumcoop.com /blogs/aquarium/clown-killifish
- fishkeepingworld.com /clown-killifish/