Species description

Care, breeding and tankmates

Fish profile

Temperament

Semi-aggressive

They are exceedingly peaceful, shy, and somewhat delicate by nature. They spend most of their time quietly stalking microscopic prey among floating plant roots. They can be easily intimidated by active tank mates and will hide constantly if stressed.

Diet

Insectivore

They are strict micro-predators requiring a diet of appropriately sized meaty foods. They thrive on live foods like newly hatched brine shrimp, microworms, and wingless fruit flies. They can often be trained to accept very high-quality, finely crushed dry flakes or micro-pellets.

Adult size

4 cm

Sex ratio

School

To minimize male-on-male aggression, it is best to keep a ratio of one male to two or three females. Males display intensely to one another but rarely cause actual physical harm if adequate space is provided. A female-heavy group ensures successful and less stressful spawning.

Feeding frequency

Twice daily

Feed them very small amounts of appropriately sized food one to two times daily. Since their mouths are tiny, food must be small enough for them to swallow whole. Ensure that the food remains at the surface long enough for them to eat.

Bioload

Low

The Clown killifish is extremely tiny and consequently produces a very low bioload. They are perfect for small nano aquariums, provided the water quality is meticulously maintained. Gentle biological filtration and regular small water changes are entirely sufficient for their needs.

Flow

Strong

They originate from stagnant or very slow-moving swamps and heavily vegetated streams. They absolutely require a very gentle flow, as strong currents will quickly exhaust them. A sponge filter is highly recommended to provide filtration without disruptive water movement.

Jump risk

Yes

Like most killifish, Clown killis are extraordinary jumpers capable of leaping through the smallest openings. A completely tight-fitting lid with absolutely no gaps is critically essential. Floating plants can help deter them from jumping by providing surface cover and security.

Reproduction

Oviparous

They are plant-spawners that will readily deposit eggs in fine-leaved plants or spawning mops. Eggs take about two weeks to hatch, and the fry require microscopic foods like infusoria immediately. Parent fish may eat the fry, so removing the eggs to a separate rearing tank is advisable.

Compatibility & tankmates

Species only

These are incredibly peaceful and timid micro-predators that are easily outcompeted for food. They must be kept with other similarly sized, highly peaceful nano fish or dwarf shrimp. Avoid keeping them with any boisterous, fin-nipping, or moderately sized fish species.

Tank level

Top

They are strict top-dwellers, spending almost their entire lives hovering just below the water's surface. They rarely venture into the middle or bottom levels of the aquarium. Providing dense covers of floating plants makes them feel secure in their preferred zone.