What part about not havbing rock formations and reefs in that region do you not understand? For that matter 99% of all of Florida except for the key area. The only rocks your gonnafind is at bay inlets and they are called jetties, and they can be hazzardous to snorkel or dive around depending on the tide......Hermits do not need any substate other than sand, and neither do sand dollars and star fish, so thats pretty much what your gonna find off the typical beaches.......Off jetties your can find urchins, and parrot fish and grunts but most if not all of these types grow too large for most aquariums. Like I said previously, you need to check laws and regulations pertaiing to harvesting of natural fauna in Florida waters, as they are not bashfull at enforcement. Some stars are protected, others are not.......all rock nbeit natural or nort is protected if it come sout of the water or even off thebeach as is lots of hard corals, but most rock and corals will only be found off the beaches in the keys.
Shrimp do not hang in jetties, they like the deeper waters of the bays or open expanses of the gulf.
I see lots of responses to two posts justy like this one already, so yu really need to check a bit more casrefully, as replies have been made.