Blue damselfish, Key Largo

I don't have a sufficient description (or photo) to determine what this fish is; I'd like to see if I can be told what it isn't.

I saw a small blue damsel on top of a rock near high-profile reef at about 28' depth at the Banana Patch, Grecian Dry Rocks, Key Largo.  The body was all-blue (no yellow noticed) with an iridescent blue eye stripe.  Depth and exposed situation suggest this was not a purple reeffish (although similar to the West Palm Beach photo in Humann's 3d ed., except that my fish had a much more pronounced eye stripe.)

The fish reminded me of the Blue Damselfish (Chrysiptera cyanea) that I had in a reef tank some years ago. says the blue damsel is "probably the best selling marine fish in the United States" so I suppose it could escape to our reefs.  I don't see it in the database.

Are there any reports of the blue damselfish in the Keys?  Or, alternatively, is the purple reeffish seen in shallow water in an exposed situation?  Or any other ideas?  Thanks. 

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