Pet sharks like those in the wild reproduce in different ways. These varied reproductive strategies help sharks give their offspring the greatest chance of survival.
Although gestation and pregnancy vary among shark species, most sharks mate the same way. Female sharks release chemicals into the water when they are ready to mate; these chemicals attract male sharks. The male shark shows interest in mating with the female by biting her. He will continue biting her during the mating process, possibly to keep them united long enough for him to pass the sperm into her body using his claspers.
Male shark’s claspers are two reproductive organs located along the inside rim of the pelvic fins. These clappers fill with semen during mating. Another tube in the clasper fills with water, which washes the semen into the female shark’s cloaca where it will move into her body to fertilize her eggs.
One of the three strategies used by shark species is ovoviviparous reproduction, also known as aplacental viviparity. With this method, the fertilized eggs hatch inside the mother. However, no placenta is available to nourish the newly hatched pups so they get their food by eating the eggs that were not fertilized and by eating smaller siblings. Consequently, only a small number of the babies survive in the litter. A number of common shark species use this reproductive strategy, including great white and tiger sharks.
Among pet sharks the most popular user of this strategy would be the Japanese wobbegong shark. With this particular species, the pups hatch and grow inside their mother for up to one year. At the end of that time, the mother can give birth to up to 27 live shark pups.
With this reproductive strategy, female sharks lay their fertilized eggs in a safe environment where they will later hatch. These eggs are covered in a tough membrane and come in different shapes depending on the shark species. A yolk inside the egg provides the nutrients for the growing baby. Neither the male nor female shark guards the nest of eggs.
Among pet sharks, the epaulette shark uses this strategy for reproduction. When the epaulette shark releases its fertilized eggs, they are stabilized by fibrous tendrils that wrap around rocks or coral nearby. Pups emerge from the eggs after approximately 120 days able to survive on their own.
Bamboo sharks, another popular pet species, also use the oviparous reproduction method. The female will lay her eggs around coral, which will help keep them in place. The eggs typically hatch approximately 100 days later.
The final reproductive strategy used by sharks is called viviparity. This method is most similar to how humans reproduce. The fertilized eggs hatch inside the mother, and the unborn pups are fed via an umbilical cord connected to the babies between their pectoral fins to a placenta. The placenta passes nutrients from the mother to the offspring. Hammerhead and lemon sharks use this method of reproduction.
Bonnethead sharks, which are sometimes kept as pets, are an example of a viviparous shark species. Gestation for these sharks lasts between four and five months. The average litter size is nine pups.