you can see fish and squids swimming happily in the ocean, but where are thier babies? well... without anyone to take care of them (thanks to mojang only adding that to land animals like cows and NOT squids and fish) they cant really make it through world generation. There is still possibility that we can find the rest and save them before they are gone. In areas where you can naturally find blue ice you could find a frozen fish or squid. by breaking them free and placing them in your furnace they can finally be free.... than despawn because thats how Minecraft works. but hey, if you give them a nametag they wont and you can keep them as a pet! this was from an idea given to me by https://www.planetminecraft.com/member/inkine/ on my forum thread about me making rushed mods based off their ideas and wishes. check it out if you want.