What is the breeding method of fish?

This time, I will explain how to breed fish.

What is the breeding method of fish?

It is very natural, but unlike humans, which are mammals, fish are classified as fish, so their breeding methods are different.

The fertilization style of fish is roughly divide into the following two types.

  • Internal fertilization
  • In vitro fertilization

Internal fertilization

This method fertilizes by mating males and females as in mammals.

Cartilaginous fish, such as sharks and rays, breed in this way, and females give birth to fertilized eggs and grown-up pups in the belly.

In vitro fertilization

The other is in vitro fertilization in which males and females release eggs and sperm. This is a method found in all teleost fish targeted as fishing fish.

Eggs released include “floating eggs” that float in water lighter than water and “sinking eggs” that are heavier than water and sink to the seabed. It is known that the method of laying sinking eggs varies depending on the species.

Childcare behavior of fish

Childcare behaviors by fish that fertilize in the body and fish that lay sinking eggs can be divide into the following three methods depending on where the child is raised.

  1. Lookout type
  2. Extracorporeal transport type
  3. Internal transport type

Let us look at each method and fish.

Lookout type

The most common type of childcare behavior is the lookout type. This is a way to raise eggs laid on rocks and seaweed on the seabed and larvae around you.

Parents use fresh water to take care of the eggs until they hatch, and ward off foreign enemies to defend them.

Kawahagi is a watch-type fish that is familiar to us. After spawning, they swim around and cover the eggs with sand to hide them from foreign enemies.

Extracorporeal transport type

The method of raising eggs and larvae by the parents themselves called the extracorporeal transportation type. It is a method of attaching an egg to the body surface of a parent or putting a child in the mouth or a special organ for childcare.

Internal transport type

The method of fertilizing eggs and fry in the abdomen by mating called internal fertilization.

It found in cartilaginous fish such as sharks and rays that fertilize in the body, and in the family of Embiotoca jacksoni.

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