All About Great White Shark Breeding and Births
Great white sharks typically reach sexual maturity between 15 and 20 years of age, with males maturing earlier than females.
Long Gestation Period:
The great white sharks gestation period for is approximately 11 months. This is one of the longest gestation periods among sharks. But, no one really knows it can be as long as 18 months
Great white sharks are viviparous, Viviparous Reproduction: means they give birth to live young rather than laying eggs. The embryos develop inside the mother’s body.
Despite their large size, great white sharks typically have small litters. A female may give birth to two to ten pups in a single litter and it is thought that only a small percentage will live past 5 years old
Nourishment from Yolk Sac:
In the early stages of development, the shark embryos are nourished by a yolk sac. As they grow, they receive additional nutrients from the mother through a structure called the placental connection.
Pup Size at Birth:
Great white shark newborns are relatively large at birth, measuring about 4 to 5 feet (1.2 to 1.5 meters) in length. This helps increase their chances of survival in the open ocean.
Nursery Areas: Pregnant female great white sharks often migrate to specific nursery areas, which are believed to provide a safer environment for giving birth and early pup development.
In California this nursery is believed to be in the California “Bite” Malibu to San Diego
Maternal Investment: Female great white sharks invest a significant amount of time and energy in the reproductive process. They may have resting periods after giving birth to replenish their energy reserves. The female white sharks we see at the Farallon Islands only migrate once every other year, this is believed that is it during this off year the female is pregnant and giving birth and in recovery
Independence After Birth: Once born, great white shark pups are fully independent. They do not receive parental care and must fend for themselves in the ocean. The mother does not play a role in the upbringing of the young sharks.
Cannibalistic Behavior: In some cases, there is evidence of cannibalistic behavior among great white shark pups inside the mother’s womb. The larger and more developed embryos may consume their smaller siblings.
Cannibalistic behavior among great white shark pups, known as intrauterine cannibalism or embryophagy, is a fascinating aspect of their reproductive strategy. Here are some additional details about this phenomenon:
Intrauterine Competition: Within the mother’s womb, there is intense competition among the developing shark embryos for limited resources. The uterus of the female great white shark has multiple compartments, each housing an embryo. The embryos are not nourished by a placenta as in mammals but rely on a yolk sac for nutrition.
Oophagy vs. Embryophagy: Great white shark embryos exhibit two types of cannibalistic behaviors—oophagy and embryophagy. Oophagy involves the consumption of unfertilized or less-developed eggs by the more advanced embryos. Embryophagy, on the other hand, is when the more developed embryos consume their smaller, less-developed siblings.
Survival of the Fittest: The occurrence of intrauterine cannibalism is believed to be a survival strategy. The stronger, more developed embryos have a better chance of surviving to birth and eventually thriving in the ocean. By consuming their siblings, they eliminate potential competitors for limited resources within the womb.
Selective Cannibalism: The cannibalistic behavior is selective, with the larger embryos specifically targeting and consuming their smaller siblings. This selective process ensures that the most robust individuals have the best chance of surviving and being born.
Size Disparities: The size disparities among shark embryos in the same litter can be significant. Some embryos may be only a few centimeters long, while others can reach lengths of over a foot. This size difference contributes to the competitive environment within the mother’s womb.
Adaptation to Scarcity: In the harsh and competitive environment of the womb, where resources such as space and nutrients are limited, intrauterine cannibalism is considered an evolutionary adaptation. It increases the likelihood that the strongest and most viable individuals will be born, contributing to the overall fitness of the species.
Research Challenges: Studying intrauterine cannibalism in great white sharks is challenging due to the inaccessibility of their reproductive habitats. Much of the knowledge about this behavior comes from examining captured pregnant females or analyzing embryos accidentally caught by fishermen.
Understanding these aspects of great white shark reproductive behavior provides insights into the challenges and strategies these predators employ to ensure the survival of their offspring in the competitive underwater environment.