The black nose is most likely from Arkansas stockings and migrations. Commonly known as the Arkansas Black Nose Crappie. They reproduce like any BC.

Some mistakenly think the black nose indicates it is a hybrid (since hybrid BC are a cross)

Here is an excerpt from JM Malone's...

The Hybrid Crappie produced by J.M. Malone and Son, Inc. is the original cross between an Arkansas Black Nosed Black Crappie* male and a white crappie female resulting in a hybrid crappie with a black stripe running down its nose. This black stripe is not an indication that a crappie is a hybrid crappie. Therefore, be advised when purchasing hybrid crappie, just because it has a black stripe on its nose does not make it a hybrid crappie.

*The Arkansas Black Nosed Crappie is a strain of black crappie first described in the white river basin of Arkansas. The black nosed black crappie have a black stripe running from the top of their dorsal fin, down their nose and over their bottom lip. The most likely explanation for this black stripe is that it acts like the black paint football players wear under their eyes helping them to see better in certain habitats. The black stripe is the result of a recessive gene like the albino channel catfish.