Has your visibility changed since last year's spawning...ie: was it less clear then, as compared to this year? I've read that often contributes to crossing.

Also, during last year's spawning, if you were short on either species' breeding age males or females, as compared to the other, that may have had something to do with it too. Not knowing which direction the cross was made.

You probably have a better idea on how these crosses occur than I do tho.

.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!