| Reproductive System |
Life Cycle:
All sharks fertilize in one of three ways.
Oviparity – Some sharks lay eggs, often protected within a leathery egg case.
Viviparity – This term is used to describe the sharks that have a placenta from which to feed and sustain their young inside. The young are born alive and at full term.
Ovoviviparity – The majority of sharks lay eggs inside their body. These hatch and the young remain inside for some time. Eventually, they are born alive and fully developed. Some shark species display a form of cannibalism in that the first pup to hatch eats the other eggs or pups while still inside its mother.
However, the bull shark follows the standard life cycle of any shark.
During mating season, bull sharks begin the mate by biting down and on the other gender. They then begin to fertilize between 8-12 "pups." After a 9 to 10 month pregnancy, the pups hatch. One of their first senses is hunting, as they are born with razor sharp teeth.
Peculiarities:
Like said earlier, sharks are all aggressive maters. They often leave dark or light visible scars on the female sharks. This is a primary way marine biologists are able to know whether or not a female bull shark could be pregnant.
Male vs. Female:
Male sharks have paired intromittent organs called claspers. Claspers are modifications of the pelvic fins and are located on the inner margin of the pelvic fins. Females do not have claspers. Male sharks have claspers which are able to insert into the female during copulation and transfer sperm into her reproductive tract. Males actually have a pair of sacs running underneath their skin that they fill with seawater before they mate.