I couldn't tell you either way, but here's what I received from the Dr.:
This gonodactylid is definitely not Gonodactylus chiragra. Looking at the color, meral spots and first maxillipeds, I would say it is probably either Neogonodactylus bredini or N. wennerae. The two are extremely difficult to tell apart. N. bredini is from the southern and western Carribean and N. wennerae tends to occur in the north and east - Florida, the Bahamas, etc. This is overlap, however.
N. wennerae often show up in live rock from Florida, so I'm guessing that this is the origin of your animal. It probably came from fairly shallow water since it is green - or has been in broad spectrum light for awhile, is about 4 years old, may live another two years and reach a maximum size of 6 cm.
Hope this helps.
Roy