The tilapia body shape is typical of the Cichlidae: very deep and laterally compressed. They have large, usually cycloid scales and a double lateral line system, one of which runs from the posterior of the operculum to a point level with the posterior end of the dorsal fin, whilst a second lateral line begins immediately below this point and continues to the tail. The anterior half of the characteristically long dorsal fin is spiny whilst the posterior half has soft, branched rays. At the base of the posterior section is a black patch, the “tilapia spot”, which is particularly apparent in juveniles and is more pronounced in some species than in others