Brown trout   Jõeforell or hõrnas   Salmo trutta trutta morpha fario 

Usually it is sufficient for a spawning milt fish, i e a male, to look his competitor squarely in the eye or to push it with his nose, and the smaller curious explorer disappears quickly (this we often see at the spawning ground). In the video the obstreperous individual is punished by a painful tug at the fin.

Flyfishers in some US salmon rivers are by the way not allowed to use artificial bait imitating  salmon fins – as we can see, with reason.

Male with its faintly visible hook (kype) remnant on the lower jaw. Screencap IceAge, LK forum