Well it clearly depends on the type of fish you are talking about here...
whales are incapable of swallowing anything larger than an orange and usually feed on small sea creatures... a shark on the other hand could easily kill a seal or any other animal for food...
Most often than not, the giants are not really the bullies in the aquatic kingdom..
It depends on what "giant fish".
some times the big fish eat the little fish
fish
Giant Squid most likely eat fish and other squid.
yes because a snake is awesome and giant fish is not cool at all
skates
12
yes they eat fish.
they usually eat insects, fish, frogs ans small water birds
Giant Chinese salamanders eat insects, frogs, and crustations.
They eat tuna,cod,if they can take down a whale they will eat it.
Giant Squida sprem whale eats squids and little fish