In Greek myth, sea god Poseidon was also the god of which animals?

Poseidon created the first horse in the competition to see which god or goddess would have the city of Athens named after them. The goddess Athena won with the creation of the olive tree.

Well, horses are good swimmers.

His Roman equivalent is Neptune while Zeus equivalent is jupiter

Now I know Poseidon Hippios the god of waters earthquick storm and the father of Horse( He invented the 1st horse)