The systematic status of the Mediterranean Spicara species (Centracanthidae) inferred from mitochondrial 16S rDNA sequence and morphological data
Fisheries Genetics Laboratory, Faculty of Fisheries, Mustafa Kemal University, Iskenderun, Hatay, TURKEY
The mitochondrial 16S ribosomal DNA together with morphological data were used to elucidate monophyly of the family Centracanthidae and interrelationships of Spicara and Centracanthus genera, including four species, Spicara maena, Spicara flexuosa, Spicara smaris and Centracanthus cirrus. Examination of the gene revealed a moderate amount of thymine and abundance of adenine. The 16S rDNA dataset contained 92 variable and 69 parsimony informative sites with a mean nucleotide diversity of 0.099. Haplotype diversity was found to be 0.71. No genetic differences were observed between S. maena and S. smaris, and the genetic divergence between S. flexuosa and both S. maena and S. smaris was found to be 0.005. The intergeneric divergence was found to be very high (0.237) between S. alta and C. cirrus. For the other Spicara species, intergeneric divergence ranged from 0.170 between C. cirrus and both S. maena and S. smaris to 0.176 between C. cirrus and S. flexuosa. Minumum evolution, neighbor joining and parsimony trees revealed same tree topologies, and the monophyly of the genus Spicara was not supported. S. maena and S. smaris clustered together and showed close relationship and S. flexuosa was nodded with this group. Therefore S. maena was found to be more closely related to S. smaris rather than S. flexuosa. On the other hand, S. alta highly divergently clustered outside of this group and branched with C. cirrus. Multivariate analysis of morphological data was congruent with the genetic data and revealed similar pattern of relationship among Centracanthidae species.
Keywords: Centracanthidae, Spicara, Centracanthus, Systematics, mtDNA, Sequence, Morphology