I strongly believe that OP staged this picture by sticking the claw of a crayfish up a fishes ass. I am a biologist, and while I mostly study behavior, I know enough anatomy to draw a few conclusions. This is the underbelly of the fish, given the lightening of scales. The fins at the bottom of the image are the anal fins, which occur right behind the cloaca of a fish. This would imply the fish ate a crayfish, the crayfish did not get digested, and wound up having its claw poking out of the anus of a fish. This simply couldn't happen. It would either a.) get digested or b.) kill the fish by getting stuck in its gut. Conclusion: The picture was staged. This is probably the most appalling thing I've seen done for karma.

source: I study fish for a living.

edit: I'm glad this got noticed, shits fucked up for real. Doesn't it seem strange that red fish parts stayed on the claw even though the fish was supposedly caught. Finally, what fish would bit a lure when its in that kind of pain. Scared/in pain fish hide, they don't bite.

tl;dr OP shoved a crayfish claw up a fishes ass for karma. THE FUCK?