Offhand I'd guess one of the
Stegastes sp. damsels -
http://www.wetwebmedia.com/stegastes.htm - but thats just a guess looking at the body shape and coloration ( I 'lost' my guide to carib. reef fishes a few years ago to a friend who never returned it...)
Nice to see I'm not the only one keeping cunner (we call em choggies) in aquaria - quite a cool fish...