Nothobranchius or notho killifish is an African freshwater ray-finned fishes genus of the Nothobranchiidae family of Cyprinodontiformes unit. These are the most bright-colored fishes among those that are kept in a tank. Their main distinctive feature is their unusual lifecycle, which is evolutionarily connected with the rain season arrival.
Fire eel (Mastacembelus erythrotaenia) resembles a true eel, that’s why the fish got its name. However, this fish has nothing in common with eels despite its snake like body and pointed snout. This is a renown tank and commercial fish.
Killifish is not very popular in aquarium husbandry and it is seldom sold in pet shops, though this is the brightest tank fish and a very fascinating one. But it’s not only the rich coloring that makes this fish so attractive. It has rather unusual spawning habit, due to which the fish is called an annotinous one. The fish hatches, reproduces and dies in a period of about a year. In the wild the fish dwells in ephemeral waters, which dry up for a period that lasts about six months.