Ceylon killifish
Aplocheilus dayi
- Endangered
- Card rarity: Epic
- Fish

The Ceylon killifish is a species of killifish endemic to Sri Lanka. It grows to a length of 9 cm (3.5 in). Males and females have a black dot at the rear end of the base of the dorsal fin. Females lay 50–150 eggs. The specific name of this fish honours the Inspector-General of Fisheries in India Francis Day (1829–1889), who first reported this fish, although he identified it as Aplocheilus panchax.
Classification
- Class
- Actinopterygii
- Order
- Cyprinodontiformes
- Family
- Aplocheilidae
- Genus
- Aplocheilus