The sea anemones would be considered the predators. they are the ones consuming.
He shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur; and he shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the Supreme Court.
This is what I ended up with.
A because Rome was in a good place so they had a lot of resources