Abstract:

In order to obtain barcods of nine Scombrid species (Thunnus alalunga, Thunnus thynnus, Euthynnus alletteratus, Auxis rochei, Katsuwonus pelamis, Sarda sarda, Scomber colias, Scomber scombrus, Scomberomorus commerson), occurring in the Turkish Seas, mitochondrial DNA Cytochrome Oxidase subunit I (COI) gene was sequenced. COI contained 177 variable and 457 conservative nucleotides of which 175 were parsimony informative over 634 bp. Mean genetic diversity within and between species were 0.002 and 0.117 respectively. The number of detected different haplotypes were 22 out of 35 sequences, and haplotype diversity was 0.96. The highest genetic diversity (0.005) within species were observed for S. commerson, and lowest genetic diversity (0.000) was observed for K. pelamis and E. alletteratus. The highest and lowest nucleotide divergence was observed between S. commerson and S. colias (0.201) and between T. alalunga and T. thynnus (0.005) respectively. In Neighbour joining tree, two main phylogenetic nodes were detected; in the first node, S. scombrus and S. colias grouped together, and in the second main node, three branches were detected on which S. commerson was branched first and most divegent from the others and sisterly grouped with S. sarda. On the other hand, A. rochei, E. alletteratus, K. pelamis, T. thynnus and T. alalunga were grouped together in third branch in which T. thynnus and T. alalunga were clustered together.

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