Colour forms of Amazonian cichlid fish represent reproductively isolated species
J. S. READY, I. SAMPAIO, H. SCHNEIDER, C. VINSON, T. DOS SANTOS & G. F. TURNER

Their work indicates that several geographical populations / colour forms of Apistogramma caetei should be
considered as biological isolated species.

"If future studies confirm that this result is indicative of a general trend, the species richness of the
Apistogramma may presently be seriously underestimated." (Ready, J.S. et al., 2006)