Clown killifish
Epiplatys annulatus
intermediate careOverview
The clown killifish (Epiplatys annulatus) is a jewel of the nano world — a fish barely 3 cm long, striped in black and cream with a fiery red-and-blue “rocket” tail on the males. It lives right at the surface of soft, tannin-stained West African streams and behaves like a tiny predator, hovering just under the film waiting for insects. Peaceful, striking and perfectly sized for a planted nano, it is a rewarding fish for a keeper who can supply soft, warm water and a securely lidded tank.
Tank & water
A small group thrives in a planted nano of at least 20 litres (5 gallons).
- Temperature: hold 22–26 °C with a small heater.
- Soft and acidic: aim for pH 5.0–6.5 and low hardness, ideally with a blackwater feel from wood and leaf litter. Test with a kit; see raising or lowering pH.
- Gentle flow: a soft sponge filter suits their calm surface waters, plus regular water changes.
- Surface cover: floating plants give security and encourage natural surface behaviour.
Feeding
Clown killifish are surface micro-carnivores with tiny mouths. They do best on small live and frozen foods — baby brine shrimp, daphnia, micro-worms, cyclops and mosquito larvae. Many will learn to take very fine floating foods, but small live foods bring out the best colour and condition, especially for breeding. Feed small amounts once or twice daily.
Tankmates
Best kept as a single-species group in a nano tank, where their colour and behaviour shine. If you want tankmates, choose only the smallest, gentlest fish that won’t out-compete them at the surface — and never anything large enough to eat a 3 cm fish. Small peaceful shrimp make good co-inhabitants. For more small-tank stocking ideas, see the best nano fish for a small tank.
Common mistakes to avoid
- An open-topped tank — surface jumpers are easily lost
- Keeping them with fish large enough to eat a 3 cm nano
- Offering only dry food when they want tiny live and frozen foods
- Hard, alkaline water instead of the soft blackwater they prefer
For another tiny centrepiece nano fish, compare the chili rasbora or celestial pearl danio, both of which suit the same small, gently planted setups.
Clown killifish — frequently asked questions
How big do clown killifish get?
They are tiny — around 3 to 3.5 cm — which makes them a true nano fish and one of the smaller killifish in the hobby. Their small size and surface-dwelling habits mean they suit a planted nano tank rather than a big community, where larger fish easily out-compete or eat them.
What water do clown killifish need?
Soft, warm, acidic blackwater conditions suit them best — pH 5.0–6.5, low hardness, gentle flow and often tannin-stained water from leaf litter and wood. They tolerate a range but colour up and thrive in soft acidic water. Test your source water with a kit before buying.
Do clown killifish jump?
Yes. As surface-dwelling fish they are prone to jumping, so a tight-fitting lid or cover glass is essential — an open-topped tank will lose them. Keep the water level a little below the rim and make sure there are no gaps around filters or cables.
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