Why do you think it is necessary for frogs and fishes to lay so many eggs?

Frogs and fishes do lay so many eggs because all of them do not get fertilised and become adult frogs and fishes . Some of them are not fertilised and some are eaten by other animals . So no of fertilised eggs are less this is the reason why female frogs and fishes ley 100's of eggs...................... Hope it help's u ....................Thank u for giving me this opportunity to answer your question.................