Descrição
Phylogenetic analysis of partial 12S and 16S mitochondrial rDNA regions, together with meristic and ethological data, has revealed that Centrolabrus trutta (Lowe, 1833), a species occurring in the Canaries and Madeira, and its close relative Centrolabrus caeruleus (Azevedo, 1999) from the Azores, are more closely related to most species of the genus Symphodus than to Centrolabrus exoletus (Linnaeus, 1758). Underwater behavioural observations showed that C. trutta, like C. caeruleus, shares with most Symphodus species sexual dichromatism, male nest building and male parental care of the eggs, traits that are absent in C. exoletus. The low number of base substitutions found between C. trutta and C. caeruleus indicates that these species are very closely related. The 16S rDNA data suggest that C. trutta, C. caeruleus and S. roissali form a monophyletic group. The analysis of the 16S rDNA data also showed that S. melanocercus is the sister species of C. exoletus and it is not closely related to the species of Symphodus included in this study. Lack of nest building and parental behaviour in S. melanocercus, and its marked divergence to other members of the genus Symphodus in meristic characters, also stress its affinity with C. exoletus and its separation from the remaining species of Symphodus. Our data and the evidence available in the literature led us to propose the inclusion of C. trutta and C. caeruleus in the genus Symphodus, while S. melanocercus must be transferred to the genus Centrolabrus.
; Almada, Frederico 
