Midas cichlids show evolution in action


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Members of the Midas cichlid species complex from the crater lakes of Nicaragua appear to be an excellent example of several different forms of evolution in action, according to a new study.

Cichlid DNA experts, Marta Barluenga and Axel Meyer of the Department of Biology at the University of Konstanz in Germany, have recently reported the findings of a recent study in the journal Molecular Ecology.

They studied seven microsatellite markers in the mitochondrial DNA (mtDNA) of Amphilophus citrinellus, A. labiatus and A. zaliosus to identify the population genetics of 519 different specimens from Lakes Managua and Nicaragua, as well as fish from crater lakes elsewhere in Central America.

The three different species can be told apart both by their physical appearance and their DNA, and they're also found in different niches. However, the pair also found that allopatrically distributed citrinellus (from different locations) differed genetically, and that there were also genetic differences in citrinellus and labiatus found living together - suggesting incipient sympatric speciation.

For more details see: Barluenga M, Meyer A. (2004) - The Midas cichlid species complex: incipient sympatric speciation in Nicaraguan cichlid fishes? Mol Ecol. 2004 Jul ; 13(7): 2061-2076