What was the first fish on Earth?

Question

Also, do you know how this fish evolved and adapted to its environment? Thanks! =]

Answer 1

cat fish

Answer 2

the first fish had legs

Answer 3

I think his name was Horace, and all the other animals made fun of him because of his name.. his younger brother  Owen was much cooler.

Answer 4

It must have been the babelfish, as evidenced by the crude and horrible way it pretends to translate languages even today.

Answer 5

The earliest recorded vertebrate 'fish' fossil is Myllokunmingia which dates back to the cambrian explosion more than 500 million years ago although it depends how loosely you want to apply the term, it had fins and swam but jaws hadn't evolved yet. If your interested in how it evolved try comparing a lamprey (which is kinda similar) to a modern day fish.