Livebearers
Fish that give birth to free-swimming young. The Poeciliids are the familiar ones; the goodeids nourish their young internally, come from a cooler climate, and include species close to extinct in the wild.
11 species, separated by adult size. Part of the freshwater fish catalogue.
Nano — under 4 cm (1)
Small enough for tanks under 60 cm, and usually needing larger groups than their size suggests.
Small — 4 to 8 cm (5)
The core of most community tanks.
Medium — 8 to 15 cm (3)
Needs real swimming length. Frequently sold as juveniles into tanks that will not suit the adult.
Large — 15 cm and above (2)
Specialist tanks. Check the adult size and the lifespan before buying.