But what does it mean, Mr. Realo?

It's a fisherman's phrase. Here's a clue. Fish are less likely to "bite you off" if you use a circle hook. That's what this fellow learned from his grandson, and even this little excerpt from his story might be enough to explain what the phrase actually means:

"Although the largest was only 13 pounds, Bluefish did not bite me off. These fish were hooked in the corner of the mouth keeping those sharp teeth away from the leader."

I have very little experience fishing. There have been times when I caught nothing more than a chunk of my own ass, so you can probably guess my intention is symbolic ....