These lands include Madagascar, India, Africa, and South America. Examples of New World cichlids that are familiar to many people as aquarium fish are the Firemouth, the Oscar, the Jack Dempsey, the Discus, and the freshwater Angelfish. Tilapias are Old World cichlids that are important as wild or pond-raised food fish in the tropics and, increasingly, in subtropical and even temperate climes.
Cichlids are highly diverse in maximum size, coloration, behavior, and ecology.
Thus, they are not easy to characterize. It is clear, nevertheless, that cichlids are a natural, monophyletic group because they possess a number of unique anatomical specializations. An excellent, easily understandable, more complete introduction to cichlids is available at Dr. Ron Coleman's Cichlid Research Home Page.