Which lines in this excerpt from elizabeth bishop's "the fish" show that the fish has given up struggling for survival after living a hard life?

I'll just post an excerpt of the poem "The Fish" by Elizabeth Bishop. The excerpt would show that the fish has given up struggling for survival after living a hard life.

"I caught a tremendous fish
and held him beside the boat
half out of water, with my hook
fast in a corner of his mouth.
He didn’t fight.                        ⇒ The fish gave up
He hadn’t fought at all.           ⇒ struggling for survival
He hung a grunting weight,    ⇒ after living
battered and venerable          ⇒ a hard life
and homely. Here and there
his brown skin hung in strips
like ancient wallpaper,"