1. Oviparity (Egg-laying)
* The process: Oviparous sharks lay eggs encased in a tough, leathery case called a "mermaid's purse". These purses are often anchored to seaweed or rocks on the seabed, protecting the developing embryos inside.
* Species: Some examples of oviparous sharks include:
* Dogfish sharks
* Horn sharks
* Nurse sharks
* Whale sharks (despite their size, they lay eggs)
2. Viviparity (Live birth)
* The process: Viviparous sharks give birth to live young. They have a placenta-like structure that allows for nutrient exchange between the mother and developing embryos.
* Species: Most shark species are viviparous, including:
* Great white sharks
* Hammerhead sharks
* Tiger sharks
* Blue sharks
Key Differences:
* Oviparous: Eggs are laid and develop outside the mother's body.
* Viviparous: Young develop inside the mother's body and are born live.
It's important to note: Some shark species exhibit a "modified" form of viviparity called ovoviviparity. In this case, the young develop within the mother's body, but they are nourished by the yolk sac of the egg, not a placenta.
Overall, the reproductive strategies of sharks are diverse and fascinating, reflecting their evolutionary success and adaptability.