Not a fisherman here, so maybe someone can explain this to me:
- If you can get your hands on the fish's belly for a whole minute, why not just grab it then and there?
- How did evolution let something like this happen? What happens if the fish swims near the bottom of the stream for a bit and happens to touch it's belly?
Fish are covered in jackets of slime. They have, for obvious evolutionary reasons, relatively few grab-points. In the belly they are convex on all sides so any squirm makes them narrower than your grasp, and they get free. The gills are a concavity that can be grasped.
It looks like it's less about "putting the fish to sleep" and more about simulating weeds with your fingers to avoid alarming the fish as you start to grab it.
Yes, you just need to work your hands into position and then grab it. I don't think that it's a good idea to do it if you aren't going to eat the fish, because I remember having to grab it very forcefully in the gills to be sure that it wouldn't slip away.
I once tried to grab a trout that was sort of stuck in a tight passage. The moment I grabbed it it immediately panicked and managed to break free from my grasp. I got wet.
If I read this correctly it would not have reacted as violently to me grabbing it if I had tickled it beforehand and I might have had an amazing trout dinner with an epic fishing tale to go with it.
- If you can get your hands on the fish's belly for a whole minute, why not just grab it then and there?
- How did evolution let something like this happen? What happens if the fish swims near the bottom of the stream for a bit and happens to touch it's belly?