The next stage of the shark life cycle starts when they are born. The extended gestation cycle of a female shark can span anywhere from five months to, in the tragic case of the frilled shark, 3.5 years. The size and shape of the “mermaid’s purses,” which are used to lay these eggs, vary from species to species. Some species, such as the zebra shark, epaulet shark, and swell shark, deposit their eggs outside the body, attaching them with tendrils to objects on the bottom to stop them from drifting away. The mother is connected to the embryo by a placenta, allowing the mother to give the pup all the nutrition it needs. However, some people practice placental viviparity, a method of conception. All shark species - around 70% of them, are viviparous, meaning they have live births. Only a few viviparous shark species exhibit omophagy. This habit is a very important part of the shark life cycle. The embryo must engage in cannibalism and omophagy in order to survive because there is no placenta. Before hatching within the female’s body, the embryo starts its existence there. Other viviparous sharks use an internal egg-laying method called aplacental viviparity. Many shark species, such as the thresher and the shortfin mako, engage in this habit known as oophagy. The embryos begin devouring their mother’s unfertilized eggs after finishing their siblings. It’s thought that this ghastly behavior is intended to guarantee that only the strongest individuals survive. While still in the mother’s body, the infant sharks have teeth that are used to kill other siblings in the belly. If a female mates with more than one guy, the babies she bears will have different dads. Additionally, after mating, the female has the option of using the sperm right away or storing it for a later time. When a female shark reaches sexual maturity, she emits pheromones, which are chemical signals that inform any nearby males that she is available for mating. The majority of organisms reproduce sexually, but some are also capable of asexual reproduction.Ĭontrary to Osteichthyes fish species, which rely on spawning or external fertilization for sexual reproduction, they reproduce sexually through internal fertilization. But we do know that there are two main ways that sharks reproduce. Since most shark species have never been seen mating in the wild, little is known about the procedure. Image source: Shark, Depositphotos Fertilization and Gestation Periodįertilization and the gestation period are considered to be the first and most important parts of the shark life cycle. The shark life cycle consists of five stages: fertilization, gestation, birth, growth, and adulthood. Adolescent sharks spend most of their time before that close to where they were born, only venturing out into deeper waters at night when the hunting is excellent. Sharks typically live for 20 to 30 years, although many don’t achieve sexual maturity until they’re 12 or 15. Sharks must ensure that every mating season is successful since they mature sexually relatively late in life, have long gestation periods, and only mate once every 2-3 years. The females of shark species that rely on fertilization will mate with multiple males to increase the likelihood that they will procreate.

Parthenogenesis is a type of sexual reproduction in which an egg develops without male fertilization. All types of sharks, including bonnetheads, blacktips, zebra sharks, and hound sharks, are capable of parthenogenesis. This may be the reason why certain shark species have evolved a different method of reproduction. This is no easy task in the frictionless ocean. His clasper, which is located on the pelvic fin, is subsequently inserted into the female’s cloaca. To keep himself in position, the male chews into the female’s torso and fins. Researchers claim that the actual fertilization process is rather complicated. 557.Before actual exploration of the shark life cycle, let’s first briefly talk about the mating habits of those interesting creatures. Fishes of the Great Barrier Reef and Coral Sea. Complete Field Guide for Anglers and Divers. Part 1 - Hexanchiformes to Lamniformes: viii, 1-250. An annotated and illustrated catalogue of shark species known to date. The Marine Fishes of North-Western Australia. Marine Fishes of Tropical Australia and South-east Asia.

Zebra shark life cycle