Least Killifish

Heterandria formosa

Also known as: Dwarf Livebearer

One of the smallest fish in the world — a tiny, peaceful native livebearer.

Water

Freshwater

Temperature

66–79°F

pH

7–8

Hardness

5–20 dGH

Max size

1.2 in

Min tank

5 gal

Temperament

Peaceful

Social

Social (4+)

Swim level

Mid

Diet

Omnivore

Care level

Beginner

Lifespan

2-3 years

Breeding

Livebearer

Suitability

Common

Origin

Southeastern USA

Despite the name it is a livebearer, not a true killifish. Peaceful and undemanding, it suits nano and shrimp tanks and tolerates cool, unheated water. Females give birth to just a few fry at a time over many days.