Registro de un Monstruo Diprósopo de Tiburón Azul (Prionace glauca) en Chile

a conjoined twins specimen of blue shark prionace glauca was collected during fishing activities in northern chile. according to a classification based on duplication degree and fusion site of the twins, it represents a monster of diprosopus tetrophthalmus type. the specimen has a partial craniofacial duplication with presence of four eyeballs and an equal number of nostrils. oral cavities are interconnected, converging in a single pharynx. the trunk is simple; the vertebral column presents thoracic lordosis and helical torsion in its caudal portion. this is the first chilean record of conjoined twins to chondrichthyan and first world record of diprosopia in sharks.