Differentiation of three commercially important southwestern Atlantic flatfishes based on osteological features

DÍAZ DE ASTARLOA, J.M. ; MUNROE, T. A.

Maizuru, Japón

Simposio; Sixth International Symposium on Flatfish Ecology; 2005

Comparative analysis of the osteology of the postcranial axial and appendicular skeletons of three south-western Atlantic flatfish species of the genus Paralichthys (P. isosceles, P. orbignyanus and P. patagonicus) was carried out. Overall shape and size of the bones are described, and detailed morphological, morphometric and meristic characteristics of these bones are provided as a taxonomic tool useful in the identification of these flatfishes.  Methods for preparing disarticulated skeletons were used for both fresh dissected and alcohol-preserved specimens.  Also, methods of clearing and staining for bone and cartilage were applied to small fishes to gain a better understanding of the size, shape and position of bones. Interspecific differences were found in the number of vertebrae and intermuscular bones, and in the morphology and morphometry of vertebrae, caudal skeleton, pectoral girdle bones, and the basipterygium of the pelvic girdle.  Relationships between bones are discussed and characteristics of the bones for these three species are compared with those found in other species of Paralichthys, as well as in other Pleuronectiform species.