The cichlids are part of the order of Perciformes. They live in South America, Africa, Asia and Europe and the known 900 species are all characterized by a dorsal fin which is divided into a hard spiny and soft spiny part. The cichlids can reach a size of up to 1m, but others are only 3cm long. The preferred water temperature of cichlids range from 22 and 30 ° C. Many cichlid species are aggressive so the welfare in a species tank is recommended. America is home to 400 different species of this popular aquarium fish.