No, they grow throught the stages of life.
the fish are hatched :D
To be correct. Fish ova (eggs) do not actually "hatch" they 'develop'. A fish egg that has developed sufficiently for it to be recognised as a fish is called a "Fry"
They are hatched from an egg.
eggs
Dory, the fish from nemo, was hatched from an egg.
A "Fry" is a recently hatched fish.
Young onotremes are hatched from eggs. They are not born live, fully developed and able to function independently of their mother like kittens and puppies can.
Newly hatched baby fish have the very distinguishing feature of an attached yellow sack hanging from their abdomen. This is the Sac fry stage, and is very distinguishable until the sac is fully absorbed.
some puffer fish hatch and are not fully developed so they form a hard shell
Newly hatched sultan fish are born with very small, soft scales. They are also much smaller than adult fish. Despite their small size, newly hatched sultan fish are able to feed themselves.
tell me what fully developed means
Newly hatched baby fish have the very distinguishing feature of an attached yellow sack hanging from their abdomen. This is the Sac fry stage, and is very distinguishable until the sac is fully absorbed.