; subclass Actinopterygii, order Perciformes)
A very large family of freshwater fish, many of which are rather deep-bodied. They have a single, continuous dorsal fin which can be very high (e.g. in Pterophyllum species, angelfish) or low (e.g. in Symphysodon species, discus fish). The lateral line is interrupted and there is a single pair of nostrils. Cichlids vary in size: Apistogramma ramirezi (butterfly cichlid) does not exceed 6 cm, but other species (e.g. Sarotherodon aureus) grow to 35 cm. Many cichlids are cultivated to supply aquarium hobbyists, being colourful, fairly easy to keep, and showing interesting behavioural traits. Other species of the genera Tilapia and Sarotherodon, e.g. S. mossambicus, are a very important source of protein in many countries. There are probably at least 700 species: most occur in Africa, but they are also found in S. America, India, and parts of the Middle East.
Subjects: Zoology and Animal Sciences.