Systematic status, variation and distribution of four Middle American cichlid fishes belonging to the Amphilophus species group, genus Cichlasoma

" Cichasoma longimanus, C. margaritiferum, C. rosratum and C. robertsoni form a complex within the Amphiophus species group. Their taxonomic history is reviewed and synonymies presented. Cichlasoma popenoei Carr and Giovannoli is placed in the synonymy of C. longimanus. C. margaritiferum known only from the type, is maintained as a valid species. Geographic variation of meristic, morphometric and color traits is discussed, but subspecies are not defined. Coloration in life, sexual dimorphism, juvenile distinctions and ecology are discussed for each species. A key is provided to distinguish the four species. The roles of historic events and competition are discussed in relation to present geographic distribution "