1, oviparous
The process of independent development of fertilized eggs in animals outside the mother's body is called oviparous. Egg-laying animals refer to animals that reproduce by laying eggs. Generally, birds, reptiles, most fish and insects are almost egg-laying animals. For example, chickens, ducks, fish, frogs, turtles and butterflies are all egg-laying animals.
2, viviparous
The process in which an animal's fertilized egg matures and produces in the uterus of a female animal is called viviparous. The nutrients needed for embryo development can be obtained from the mother until birth. Embryos absorb nutrients and oxygen from maternal blood through placenta and umbilical cord during development, and at the same time send metabolic wastes to the mother. The fetus is directly produced by the birth canal after its development in the mother's uterus.
Exotic reproduction of animals:
1, hippocampus
Hippocampus has always been a special kind of marine life, and its reproduction mode is that females lay eggs, which are then discharged to males and fertilized in the male hippocampus. This is because the male of this animal, the hippocampus, has one more organ than other animals, that is, the incubator, also known as the pouch.
2. Incubate the eggs until the exhausted octopus.
Octopus, as the smartest animal in the ocean, will reproduce "by suicide". After mating between the female octopus and the male octopus, the female octopus will lay a large number of octopus eggs in the nest. Because of the nature written in their genes, the female octopus will stay in the nest to look after her eggs, and from time to time, she will touch those egg sacs with her tentacles to prevent them from dying of lack of oxygen.
3. Eat the male mantis after mating
Mantis is a dioecious insect, so it is necessary to breed offspring through mating. During mating, the male mantis will fly to the female mantis and then start mating. After mating, most female mantis will eat the male mantis.