RE: ID please
It is definately a juvenile (hence living in sargassum weed) and being from the Gulf, it is probably a sea bass or a snapper. Most pictures I have only show the adult coloration so it is very hard from the pictures to be sure. You will probably have to wait until it grows up to make a positive ID. Also, if it is a sea bass or snapper, this fish will get very large and is a carnivore so you will need a very large tank and be able to feed it lots of meaty foods. Good luck and send us some pictures in 6 to 12 months as we should have a much better idea by then as it fills out.
135 gallon reef and 29 gallon mini-reef.