Examination of Genetic and Morphologic Structure of Sea-Bass (Dicentrarchus labrax L., 1758) Populations in Turkish Coastal Waters


Abstract: In this study genetic and morphologic structure of the sea-bass, Dicentrarchus labrax, in Turkish coastal waters were studied. Total 120 individuals were sampled in equal numbers from the Black, Marmara, Aegean and North-eastern Mediterranean Seas. In genetic analyses, four-enzyme systems (G3PDH*, ME*, MDH*, PGI*) were assayed, representing 9 loci (G3PDH-1*, G3PDH-2*, MDH-1*, MDH-2*, MDH-3*, ME*, PGI-1*, PGI-2*, PGI-3*), 2 of which were polymorphic (G3PDH-2*, PGI-3*). Fisher's exact test revealed that there were no genetic differences between populations using 9 loci. Nei's genetic distance was 0.0001 between the Black Sea and Mediterranean samples. Genetic identity was also found to be 0.9999 between the Black and Mediterranean Sea samples. In canonical discriminant function analysis, a high degree of morphologic differentiation was detected between populations. Proportions of correctly classified Aegean Sea (100%) and Black Sea (97%) samples to their original group were highest. Plotting discriminant function 1 and discriminant function 2 separated all the populations from each other, showing a high degree of morphometric differentiation among populations.

Keywords: Dicentrarchus labrax, stock structure analyses, genetic, morphologic, Turkish coastal waters

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