Tilapia stock identification using electrophoretic markers

Abstract

With the difficulties in the identification of the many tilapia species, a reliable method independent of morphological characteristics was 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 has shown that a large amount of co-dominant interspecific variation exists which may be used to identify unequivocally the nine different species studied. The technique and relevant buffer systems and stains are described together with an account of the enzymes observed and their interpretation. 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.