Reproduction

Bull shark breeding season is during summer, usually end of April to early June. They tend to mate in the water of river mouths, which is where a river flows into a larger body of water. During copulation males often bite the female on the pectoral and pelvic fins, sometimes near her head. Bull Sharks are known to be polyandrous, meaning they often have multiple partners rather than sticking to one mate their whole life. Males usually reach sexual maturity at 15 years old and females at 18. The late sexual maturity of bull sharks is likely an adaptation to their reproductive strategy. As a viviparous species (explanation in fertilization), bull sharks invest more resources into producing fewer, higher-quality offspring rather than relying on large numbers of offspring. Doing so allows bull sharks to grow larger and produce more viable young over their lifetime. 

Since the gestation period lasts 11 months on average, Bull Sharks tend to give birth around the same time they mate, during summer. As the gestation period comes to an end, the mother will move to a flat, protected area far away from predators and close to food. Once the pups are born the mother will leave and take no part being involved in raising the babies (same with the father). Since the pups develop in the womb, they come out very grown, up to nearly 4 ft. All Bull Sharks become fully developed at 15 - 20 years.