How animals/fish raising means of livelihood?

Fish farming or pisciculture involves raising fish commercially in tanks or enclosures such as fish ponds, usually for food. It is the principal form of aquaculture, while other methods may fall under mariculture. A facility that releases juvenile fish into the wild for recreational fishing or to supplement a species' ... In the European Union, fish labeling as to species,  ...

Explanation:

what school and grade?