Abstract
Development of median and paired fins and their supports are described for Paralichthys olivaceus, giving details on origin, shape, ossification and meristic counts.All fin supports begin to form through cartilage in the following sequence: pectoral (2.62mm SL), dorsal (4.60mm SL), caudal (5.55mm SL), anal (5.95mm SL) and pelvic fin support (8.57mm SL).Completion and partial ossification of fin structures are already present by the 40th day after hatching (ca.16mm SL), after eye migration.This study shows how developmental osteology may clarify identification and terminology of fish bones (e.g., caudal skeleton).Comparisons with other species belonging to Pleuronectiformes elucidate basic pattern of fin formation within the order, and depict interesting departures which may be of taxonomic and/or systematic utility.
