A new study examining the genetics and mate choice patterns of a dwarf cichlid from South America have shown that what were previously considered colour morphs of a single fish are actually distinct biological species.
An international team of scientists, including Professor George Turner of the University of Hull, examined Apistogramma caetei morphs in the laboratory in a combined molecular and behavioural study.
Their findings, which have just been published in the Journal of Evolutionary Biology, show that Apistogramma caetei is made up of at least three allopatric lineages which only mate with others of their own form, making them species under the Biological Species Concept.
If the same techniques are used to examine other species believed to be made up of colour morphs it could mean that the number of cichlid species in South America has been seriously underestimated, the scientists suggest.
For more information see the paper: Ready JS, Sampaio I, Schneider H, Vinson C, Dos Santos T, Turner GF (2006) - Colour forms of Amazonian cichlid fish represent reproductively isolated species. J Evol Biol. 2006 Jul ; 19(4): 1139-48