As a diver and Marine Conservation Biologist... fish, especially juveniles hold a special place in my studies and my heart. This is a late stage juvenile Spotfin Butterfly Fish. Native range is Western Atlantic from North Carolina to Brazil. Most common on reefs in Caribbean and Gulf of Mexico. This little fella was found off Rhode Island. It is not uncommon for the planktonic floating eggs of this species to get carried up the Atlantic Coast in the Gulf Stream. When a warm core ring spins off the Gulf Stream and into Long Island Sound, the larval fish get deposited in the relatively shallow waters and have to make the best of it. Most are dead by November as temps in the sound and New England waters begin to precipitously drop well below their tolerance. A few lucky ones get collected by marine scientists and aquariums such as the Mystic and New England Aquariums. This one was a lucky one.

https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/chaetodon-ocellatus/