Clown killifish

Identity and search names

Single-species profile for Epiplatys annulatus. Pseudepiplatys annulatus is a synonym retained for search continuity. Search names: rocket killifish, Pseudepiplatys annulatus

Environment and housing

Completely sealed lid, floating plants, dark substrate, gentle filtration, calm surface lanes and no gaps around cables or pipes

Feeding and nutrition

Feeding ecology: Surface micropredator taking tiny insects, crustaceans and appropriately sized floating foods

Feeding routine: Offer tiny floating or slowly sinking foods once or twice daily across several surface points

Breeding and reproduction

Non-annual plant or mop spawner; eggs develop outside the adults and fry need minute first foods

Parental care: No parental care; adults may eat eggs or fry

System demands

Filtration: Use mature biological filtration sized for the adult stock and feeding load, with guarded intakes and a flow pattern the species can use without continual effort.

Aeration: Maintain strong gas exchange and stable dissolved oxygen, especially overnight, during warm weather, medication, crowding or any interruption to filtration.

Maintenance: Test ammonia and nitrite after changes or abnormal behaviour; remove waste from the occupied zone and perform regular water changes matched to temperature and mineral chemistry.

Detailed husbandry

Identity scope

Single-species profile for Epiplatys annulatus. Pseudepiplatys annulatus is a synonym retained for search continuity.

Adult size and space

Up to about 4 cm total length. At least 50 L with a long calm surface for a group of six or more. Adult dimensions, activity, social structure and waste production matter more than sale size.

Social structure

Small group of at least six with more females than males and several surface retreats

Swimming zone

Primary zone: Surface and upper water. Keep that zone usable and provide unobstructed feeding access, movement and refuge appropriate to the species.

Feeding ecology

Surface micropredator taking tiny insects, crustaceans and appropriately sized floating foods

Feeding plan

Offer tiny floating or slowly sinking foods once or twice daily across several surface points

Water stability

Maintain 20–26 °C; pH: 5.5–7.5; hardness/minerals: Soft to moderately soft. Stable temperature, oxygen, mineral chemistry and nitrogen-cycle control matter more than chasing a single exact number.

Habitat structure

Completely sealed lid, floating plants, dark substrate, gentle filtration, calm surface lanes and no gaps around cables or pipes

Compatibility plan

Use tiny peaceful lower-water companions that cannot eat them or dominate the surface

Breeding plan

Non-annual plant or mop spawner; eggs develop outside the adults and fry need minute first foods. Parental care: No parental care; adults may eat eggs or fry. Do not trigger reproduction without capacity for aggression, eggs or fry and lawful long-term placement.

Quarantine

Quarantine new fish in a separate cycled aquarium with dedicated nets, containers and siphons. Match temperature and mineral chemistry gradually, confirm normal feeding, respiration, skin, fins and waste, and never pour transport water into the established aquarium.

Welfare checks

Check lid seals, surface access, body fullness, male display pressure, feeding capture and whether any fish is being driven away from floating cover.

Biosecurity and release

Never release fish, eggs, fry, aquarium water, sediment, plants or foods into drains, dams or natural waterways. Check the exact accepted identity in current BICON, Australian live-fish import requirements and applicable South Australian rules before import, sale or movement; import eligibility does not authorise release or wild collection.

Main risk

Small lid gaps are escape routes, and larger fish will eat them. A generic killifish label is not enough because annuality, size and predatory behaviour vary sharply among species.

Adult Projected Load

Low by biomass, but a proper group needs secure surface area, tiny foods and low competition; losses occur quickly through jumping or starvation.

Filtration

Use mature mechanical and biological filtration with protected intakes and enough turnover for the adult group while preserving species-appropriate current and refuge.

Aeration

Provide strong gas exchange and backup aeration; increase oxygen support before warm weather, heavy feeding, crowding, medication or filter interruption reduces the safety margin.

Maintenance

Remove uneaten food and bottom waste, clean prefilters before flow falls, test ammonia and nitrite after changes, and perform regular temperature- and chemistry-matched water changes.

Overridable Warnings

A tight lid, calm surface access, group size and tiny-food availability cannot be overridden.

Welfare and risk

Check lid seals, surface access, body fullness, male display pressure, feeding capture and whether any fish is being driven away from floating cover.

Sources

• Eschmeyer’s Catalog of Fishes — Epiplatys annulatus — Accepted name, synonym and taxonomic placement
• American Killifish Association — Epiplatys annulatus — Accepted aquarium identity, distribution and reproductive context
• IUCN Red List search — Epiplatys annulatus — Conservation and provenance cross-check
• Australian Government — importing live ornamental fish — Australian import pathway and biosecurity requirements
• PIRSA — South Australian noxious fish list — South Australian possession, trade and release context
• Eschmeyer’s Catalog of Fishes current search — Epiplatys annulatus — Current accepted-name, synonym, distribution and habitat cross-check