Cephalic and pectoral girdle muscles of the clupeiform Denticeps clupeoides , with comments on the homologies and plesiomorphic states of these muscles within the Otocephala (Teleostei)

The muscles of the cephalic region and pectoral girdle of Denticeps clupeoides are described and compared with those of other otocephalans (= clupeomorphs + ostariophysans). In general, the configuration of the cephalic and pectoral girdle muscles of Denticeps seems to correspond to the plesiomorphic condition for extant otocephalans, the main exceptions being: the dilatator operculi, which is rather small and is to a great extent covered in lateral view by the preopercle; the arrector dorsalis, which is not divided into two well-differentiated, separate sections; the protractor pectoralis, which is missing. Comments on the homologies, plesiomorphic states and evolution of the cephalic and pectoral muscles within the Otocephala are given.