A wild conclusion
When I catch a stocked trout, pick it up in my hand and hold it belly-up while unhooking, I feel that holding it in this upside down attitude tends to immobilize him. I seem to be able to unhook him without his wiggling very much less than if he is belly down. Could it possibly be that he has never been in this attitude before and is disoriented. I might be really off base on this but would appreciate comments. Thanks.
"Tonic Immobility" is a condition where sharks, when held upside down, seem to go to sleep, allowing them to be handled safely. In fact, at least one, maybe two, pods of Killer Whales have learned this, and use this to immobilize, kill, and eat sharks.
I wonder if Tonic Immobility happens with all fish?
I've seen trout flipped over on their backs, grazing (or would it be browsing?) on scuds/cressbugs in spring creeks. Don't know if maintaining this position over an extended time would lead to Tonic Immobility (love that phrase).
I have found it's the same with most fish, Trout, Kahawai, Trevaly, Snapper etc if you hold them upside down they struggle less and are easier to unhook.
All the best.
Same here. I always try to hold upside down