Black or white crappie - which more important color or fin rays?

This fish was collected last year from a turbid slough in extreme SE OK. We've had a lot of interesting debate regarding it's identification and I'd like to hear from others.
We initially thought it to obviously be a black crappie. However, it was breeding season, and even though we sometimes catch dark white crappie we had never collected a black crappie in this water body.
Of course breeding white crappie can be very dark, but if this is a white crappie it's the darkest we've seen.
Anyway, it clearly has the shape and color of a black crappie, but the dorsal spines are 6. There are no spines laying down or not shown in the photo. For about the last year, we have debated on which is more important in this case. Color or spine count.

Today, we stumbled an old key which advised measuring the distance from the eye to the base of the dorsal. If the distance is greater than the length of the dorsal base, it's white crappie. If it's about the same it's black crappie. However, this method hasn't proven conclusive because:
1. There are several ways one could measure from the eye to the base of the dorsal. Does anyone know the correct method?
2. Several have measured the distance from the eye to the dorsal base to be about 7-10 mm greater than the length of the dorsal base (assuming we measured from the correct location on the eye). So 7-10 mm is greater, but it's also "about" the same. This leaves us back where we started.

If we still had the fish we would send it to the genetics lab, but too late for that now. Anyone have a good method of finally putting the true ID of this fish to rest? I tend to place spines over color, but some keys list white crappie as 6 spines, while others say usually 6.

Anyone want to offer their thoughts?

I would call that a Black Crappie.

Fish could be hybrid. About three years ago we generated F1 hybrids for a feeding trial. Coloration favored black while dorsal spine count and dorsal fin to eye measurements where intermediate. None of those fish where photographed in breeding dress but they where fertile which caused problems last spring in breeding pond.

Centrarchid, What is the correct method to measure dorsal fin to eye?

I think you measure from the front of dorsal fin base to the back of the eye. For Black Crappie, Fishes of Arkansas says, "Length of dorsal fin base equal to or greater than distance from front of dorsal fin base to back of eye." For White Crappie it says, "Length of dorsal fin base much less than distance from front of dorsal fin base to back of eye."

As you noted above, the length of the dorsal fin base on your fish is a little less than the distance from the dorsal fin base to the back of the eye, indicating White. However, I'm not sure that the distance qualifies as "much less". The 6 dorsal spines also point to White. My book says 6 (sometimes 5) for White and 7 or 8 for Black. The coloration points to Black. I was taught to generally put more stock into meristics and morphometrics than coloration, so I would lean towards White or, like Centrarchid said, hybrid.

Thanks for clarification on the measurements. I also tend to trust meristics and morphology more than color. We've found fish don't always follow the rules, when it comes to ID.
For example, according to some keys spots are inconspicous or absent on a longnose gars head, but there are exceptions........