He is watching if the invader goes away or stays in the teritory. The owner AYU is wondering if he should fight or not. He is getting mad now. He is ready to fight. He attachs on his belly bottom.
Poor fish is caught.
Hooked on the shoulder where it does not hurt the fish. You pull two fish into your net. You change the fish. The one you just caught is now your invader fish to get another fish. When you catch the next fish, you change again.