Cichlidsare fish from the family Cichlidae in the order Perciformes. The family Cichlidae, a major family of perciform fish, is both large and diverse. There are at least 1300 scientifically described species, making it one of the largest vertebrate families. Numerous new species are discovered annually, and many species remain undescribed. The actual number of species is therefore unclear, with estimates varying between 1300 and 3000 species, and one source suggesting 1900 species. Cichlids span a wide range of body sizes, from species as small as 2.5 centimetres (1.0 in) in length (e.g. female Neolamprologus multifasciatus ) to much larger species approaching 1 metre (3 ft) in length (e.g. Boulengerochromis and Cichla). As a group, cichlids exhibit a similarly wide diversity of body shapes, ranging from strongly laterally compressed species (such as Altolamprologus, Pterophyllum, and Symphysodon) through to species that are cylindrical and highly elongate (such as Julidochromis, Teleogramma, Teleocichla, Crenicichla, and Gobiocichla). Generally, however, cichlids tend to be of medium size, ovate in shape and slightly laterally compressed, and generally very similar to the North American sunfishes in terms of morphology, behaviour, and ecology.