Molecular and otolith shape analyses of Scorpaena spp. in the Turkish seas

Abstract

This study aims to investigate the discrimination and the phylogenetic relationship of five Scorpaena species (S. elongata, S. maderensis, S. notata, S. porcus, and S. scrofa), sampled from eight locations in the four seas (Mediterranean Sea, Aegean Sea, Black Sea, and Sea of Marmara) in Turkey, using both molecular and otolith shape analyses. Totally, 1360 samples were examined for otolith shape analyses, and 51 of them were also used in the molecular analysis (COI sequences, 652 bp). Eighteen haplotypes were determined in the 5 species of the genus Scorpaena; 3 haplotypes for S. elongata, S. maderensis and S. scrofa, 4 haplotypes for S. notata, and 5 haplotypes for S. porcus. The highest interspecific genetic distance was observed between S. maderensis and S. notata (0.1569), and the lowest interspecific genetic distance (0.0527) was observed between S. elongata and S. scrofa. The lowest interspecies genetic distance was found to be considerably higher than the highest intraspecies genetic distances for these five Scorpaena species. The barcode range in the study alone provided a high rate of barcoding success in identifying species belonging to the genus Scorpaena. A Principal Component Analysis (PCA) and Canonical Discriminant Analysis (CDA) were conducted for interspecific discrimination of the five Scorpaena species. The CDA produced an overall classification success rate of 96.3% with the highest rate for S. scrofa (98.8%), followed by S. maderensis (97.5%), S. notata 96.6%), S. elongata (94.6%), and with the lowest rate for S. porcus (94.4%). The results indicated that molecular analysis was generally compatible with otolith shape analysis and confirmed that otoliths have phylogenetic signals for Scorpaena species. This is the first study in which five Scorpaena species sampled from eight locations in four seas have been distinguished using both otolith shape and molecular analyses.