First record of dicephalia in a bull shark Carcharhinus leucas (Chondrichthyes: Carcharhinidae) foetus from the Gulf of Mexico, U.S.A.

The first recorded incidence of dicephalia in a bull shark Carcharhinus leucas is reported from a foetus collected by a fisherman in the Gulf of Mexico near Florida, U.S.A. External examination, Radiography and magnetic resonance imaging revealed a case of monosomic dicephalia where the axial skeleton and internal organs were found to divide into parallel systems anterior to the pectoral girdle resulting in two well-developed heads. [ABSTRACT FROM AUTHOR]