All fish / Aplocheilidae

Ceylon Killifish

Aplocheilus dayi

Also known as day's killifish, ceylon panchax, green panchax, day's panchax, aplocheilus dayi dayi, アプロケイルス・ダイ, 斯里兰卡蓝眼灯

A slim, pike-shaped killifish with a flat back and upturned mouth, males showing greenish to golden flanks dotted with red spots and fins edged in yellow and red. It patrols just under the surface hunting insects, and is kept for its colour, hardiness and interesting surface-predator behaviour.

Care at a glance

Care level

Easy

Temperament

Semi

Adult size

7 cm

Temperature

22 to 28 °C

pH

6 to 7.5

Smallest tank

60 litres

Keep as

A pair or one male with two or three females

Diet

Carnivore: insects, bloodworm, brine shrimp, daphnia, and floating pellets or flakes

Swims

Top of the tank

Lifespan

2 to 4 years

Water

Freshwater

Wild range

Sri Lanka (lowland wet zone streams and marshes)

Breeding

A non-annual egg scatterer that lays adhesive eggs among fine-leaved or floating plants and spawning mops over several weeks. Eggs hatch in about two weeks and fry take newly hatched brine shrimp, so breeding is fairly easy if eggs are removed from the adults.

Good to know

It will eat very small fish and shrimp, and is a strong jumper so needs a tight lid. Endemic to Sri Lanka where it is threatened in the wild, so captive-bred stock is preferable.