Date of this Version
The distribution of freshwater fishes in Central America is reviewed. Major parts of the region, especially in Honduras and Nicaragua, have yet to be explored ichthyologically, and systematic revision of important groups, notably the cichlids, is long overdue. The continental area from the Isthmus of Tehuantepec to the Colombian border contains approximately 456 species, of which over 75% comprise the Cyprinodontidae, Poeciliidae, Cichlidae, and marine invaders (peripheral fishes); about one-third of the latter (57 species) have taken up more or less permanent residence in fresh water. There are 104 primary species in 10 families, 165 secondary forms in 6 families, and 187 peripheral species distributed among 30 families (nearly half of the latter are ariids, atherinids, gerrids, and gobies). Poeciliids and cichlids are particularly rich and diverse, together comprising 139 species. Characins are numerous only in the Panamanian region, into which they and five South American catfish families have recently penetrated. Except for gars, no North American family has reached beyond northern Guatemala. There are no non-ostariophysan primary fishes in the area.