Pondering ID of this NJ River fish

[teleost]

actually the more I look at it is a green sunfish. Rock bass have some red and black in the sides. very similar fish though.

Actually not similar at all. They aren't even in the same genus!
Again this is a situation where books really pay off and promote fast and easy learning. Rock Bass are Ambloplites genus which all have 6 anal spines and Green sunfish are Lepomis genus and only have 3 anal spines. A book would point that out to you right away and you'd probably never forget it if you read a book.