My initial thought was the same a Mr.X that it was an Orbicuaris bat only the fins had been chewed off however, there seems to be 2 fish in your picture that have the same shape and/ or deformity which was why I went towards Juv. Spadefish. Just being from the pacific no longer applies as the Atlantic ocean is now filled with Pacific lionfish species so there is no reason why someone couldn't have released Spadefish in the Pacific.But this pic you show me when it is small like a 5 cents coin it is grey with stripes, this one was found in the Pacific Ocean and it is orange red with yellow and black dots with one stripe that goes by the eye
I'm guessing Chaetodipterus zonatus ...so the eastern Pacific counterpart of the Atlantic spadefish.
Tony