The stringer picture shows at least two white crappies (bar pattern) and to me the one you are holding looks like a black crappie due to the markings but he there is a lot of space in front of the dordal fin for a black crappie. But yes the spine count is the way to tell for sure.
Be aware they will hybridize sometimes where both species are found, and I've mounted fish that had the spine count of one species but the markings of another and vice versa.
