Tilapia stock identification using electrophoretic markers.
With the difficulties in the identification of the many tilapia species, a reliable method independent of morphological characteristics is needed to define the nature of the cultured stocks throughout the world. Starch-gel electrophoresis of various body tissues and the resolution of protein loci using specific histochemical techniques showed that a large amount of codominant interspecific variation exists which may be used to identify unequivocally the 9 species studied. The technique and relevant buffer systems and stains are described. The results are expressed as relative mobilities of the observed isozyme bands, allowing direct comparison between all the species studied. The potential of the technique is discussed regarding its possibilities in tilapia culture and in the general genetic improvement of stocks.