Killifish
Killifish are beautiful, small, easy to keep, easy to breed, and don't need a large amount of space. There is no reason that they are so rare. Killifish don't actually kill fish; the word killi means creek or small stream in Dutch.
Asian Killifish
There are only a few species of Asian Killifish, they are all 4 in., and they come from the family Aplocheilus. They like rather warm and acidic to neutral water. The most popular killifish is the 4 in. Golden Wonder. Another 4 in. killifish, the Blue Panchax, is more rare than the Golden Wonder. Other Asian Aplocheilus' are werneri and red panchax.
A male blue panchax. He is not in breeding colors.
A female blue panchax. A lot fatter than the male.
Aphyosemion
These killifish are beautiful, but most of them are rare. They like acidic water and are very flexible with temperature. All of the aphyosemion are about 2.5 in. long. The cape lopez lyretail is probably the most common aphyosemion.
Fundulopanchax
This is another beautiful group of Killifish. They like the same water as the Aphyosemion. Fundulopanchax Gardneri is the same size as most other Fundulopanchax, which is 2.5 in. The Blue Gularis is the only Fundulopanchax bigger than 3 in. and the only one that is a peat spawner. Other Fundulopanchax are Fundulopanchax spoonbergii, akure, cinnomannum, and scheeli.
Annual Killifish
These rare fish are beautiful but only live for a year. They lay their eggs before the small pools that they live in dry up. When it dries the eggs remain dormant until the rain comes and the parents die. They like warm, acidic water. The 2 in. Nothobranchius killies are Nothobranchius guentheri and ranchovi. 5 in. annuals include the blue gularis and the golden pheasant.
US Native Killifish
These killifish are all coldwater except for the flagfish. They like neutral water. Killies of the Fundulus family get 4 in. long and need to be collected in the wild if you want any. Flagfish and other pupfish are only 3 in. or less. Studfish are some of the largest killifish, reaching 7 in. long.
Lampeyes
Lampeyes are African killies that need warm, neutral water. The smallest lampeye is the Normani Lampeye, at only 2.5 in. The giant lampeye gets 8 in. long.
