Most young fish feed themselves.
Fish as a rule, aren't very caring parents. Once the eggs are fertilized, most species will simply leave them to survive best as they can on their own.(Do note that there are some rare exceptions...
Well they don't feed them with milk or anything because they are not mammals. They could get food for them, like birds, though.
Yes they do
No. Mammals are the only animals to do this. Now if you mean whales and dolphins, those do, since they are also mammals.
no