A single litter of bull shark pups can have two fathers, say French researchers.
The scientists tested the embryos from four bull sharks (Carcharhinus leucas) in Reunion Island. They found that two of the sharks contained litters from two different fathers. This is the first time this has been demonstrated in bull sharks.
Multiple paternity is common in many species. It has been suggested that females engage in multiple mating to increase the number or quality of their offspring.
Bull sharks live in tropical and sub-tropical waters around the world. Bull sharks are viviparous – giving birth to living babies like mammals rather than eggs. Their litters contain between one and fourteen pups.
Pirog, Agathe, Jaquemet, Sébastien, Soria, Marc, and Magalon, Hélène (2015). First evidence of multiple paternity in the bull shark (Carcharhinus leucas). Marine and Freshwater Research