Killifish
Small freshwater fish with extraordinary colours. Many species lay eggs that survive dried in the mud for months.
Detailed explanation
Killifish are among the most colourful freshwater fish in the world. The males of Nothobranchius and Aphyosemion rival marine fish for the vividness of their colours.
Annual species (Nothobranchius) live in seasonal pools in Africa. They lay their eggs in the substrate; when the pool dries up the eggs survive in the mud and hatch with subsequent rains.
In aquariums the eggs are preserved in moist peat for 3-6 months and then immersed in water for hatching. It is a unique type of breeding.
The non-annual species (Aphyosemion, Fundulopanchax) are longer-lived and less demanding.