I know exactly what that is. It is a kind of sunfish (also called bream). They get about 8 inch to a foot and will eat your mosquito fish you have. They are territorial but not too aggressive. Can't tell you what kind it is because the quality is not that great and it is not underwater but o well. It might be a red ear or a redbreast. It might be a green sunfish. But i don't think it is a spotted. Where in Florida do you live? I am on the east coast in Lehigh, which is close to Ft. Myers.