Genetic and morphometric evidence for unresolved species boundaries in the coral genus Psammocora (Cnidaria; Scleractinia)

A comparative morphological and molecular characterization of species boundaries between four species of the Scleractinian genus Psammocora, namely P. digitata, P. haimeana, P. profundacella and P. contigua was conducted. The definition of species boundaries in this genus has been the subject of few studies, in spite of the presence of ambiguous taxonomic distinction, and a revision of the genus has never been undertaken. The multivariate analyses of both descriptive and morphometric characters confirmed the distinction of P. digitata and P. contigua, conversely P. haimeana, P. profundacella and their intermediate morph differentiated on the basis of descriptive morphologic characters only. Morphometric characters alone allowed a less defined distinction between morphs, and morphological boundaries essentially intergraded in a gradient driven by enclosed corallite series characters.