1. Internal Fertilization: Tiger sharks, like most sharks, reproduce through internal fertilization. The male uses claspers, specialized appendages near the pelvic fins, to transfer sperm into the female's reproductive tract.
2. Viviparity: Tiger sharks are viviparous, meaning they give birth to live young. They do not lay eggs.
3. Ovoviviparity with Histotrophic Nourishment: This is where it gets interesting. While the embryos develop inside the mother's body, they are initially nourished by yolk sacs. However, after the yolk sac is depleted, the embryos transition to a unique form of nourishment known as histotrophic nourishment. This means they receive sustenance directly from the mother's uterus through a specialized uterine fluid, rich in proteins, lipids, and other nutrients. This fluid is often referred to as "uterine milk".
4. Litter Size and Gestation: Tiger sharks can produce litters of up to 80 pups, though the average is closer to 30-50. Gestation periods are long, typically lasting around 12-16 months.
5. Cannibalism: One intriguing aspect of tiger shark reproduction is the possibility of intrauterine cannibalism. In some cases, the largest and most developed embryos may consume their smaller siblings within the uterus, a phenomenon known as adelphophagy. This behavior is believed to help ensure the survival of the strongest offspring.
6. Size and Maturity: Tiger shark pups are born relatively large, often measuring around 3-4 feet in length. They are independent from birth and capable of hunting on their own. Sexual maturity in tiger sharks is slow, taking several years for both males and females to reach reproductive age.
Overall, the reproductive strategy of the tiger shark is characterized by:
* Internal fertilization
* Viviparity with a unique form of histotrophic nourishment
* Large litter size and long gestation period
* Potential for intrauterine cannibalism
* Slow maturity
This complex strategy ensures a degree of success in a challenging environment, allowing these powerful predators to thrive in diverse marine ecosystems.