Aggressive behavior among Arctic Graylings DSC_6406
I have seen this a lot but didn't realize I captured it. In going back through images from 2014, I discovered this capture of aggression among fish. The male on the left is attacking the make on the right by biting it in the side. This caused the male Arctic Grayling (Thymallus arcticus) on the right to give way and move off.
Interaction among fish happens so fast it is luck to be able to swing on it without other fish in the way and capture the behavior. This happens all over a spawning stream during the season.
Image taken in North Park, Colorado.