Oviposition is what we usually call "oviposition". The eggs laid by sharks have egg sheaths, and the skin will harden when exposed to water. Each corner has a hollow corner, which allows seawater to come in, thus providing oxygen for the eggs inside. Generally speaking, big sharks lay eggs. Lemon sharks and hammerhead sharks are viviparous. Tiger shark is a typical viviparous, viviparous, viviparous is similar to viviparous, and it also breeds embryos.