they don't get tired because there designed to swim.
to swim
no,but they have oil rich livers.It prevents them from sinking when they are not swimming. but some fishes have swim bladders. ex:guppies,goldfish..........
Thats how they swim
they swim
Yes, all whales are fishes because they swim like fishes.
separate vertebrate
salmon
they swim not run
Yes they can swim.
Yes. Fins, a swim bladder, the composition of their bones, and their muscles all help a fish to swim.
Nope. Piranhas are freshwater fishes.
they die