Living fish are used as bait to catch other fish. Hooks and line may be passed through parts of the fish, including the eyes. The fish may die when the target fish is caught, or eventually after time.
Book: The Complete Guide To Coarse Fishing
Author: Alan Wrangles
"Remember to pass the hook through the top lip only; if both lips are caught on the hook the bait is prevented from breathing correctly and will therefore soon die."
"Small fish should keep quite well for a few days in a large bath."
"Although expensive, goldfish bought from a pet shop can be used for spinning or live baiting. The brilliant colour of the goldfish makes it a very attractive bait."
"For pike spinning, mount the sprat on a tackle fitted with a body pin which is inserted right into the mouth of the fish. Secure the treble hooks to the sides of the sprat with several turns of thread."
Article: I Was a Fish Killer
Author: Steve Hindi, SHARK (Showing Animals Respect and Kindness) President
"Often we bought large sucker minnows as bait."
"The suckers were hooked just under and to the rear of the dorsal fin, in a way that would allow as much movement as possible, and would maximize their survival time."
"Some fishers would run the hook through their eyes. The suckers were thrown out and suspended under a bobber, or were held close to the bottom by a lead sinker. The bobber was big enough to prevent the minnow from pulling it underwater, but small enough to be taken down by a larger predator as it grabbed the minnow."
"Although we were told, and wanted to believe, that fish did not feel fear or pain, we almost always knew when a predator approached the sucker. The bobber would begin to bounce and move; although the sucker wasn’t big enough to sink the bobber, his or her panic was obvious."
"The bobber jerked, pulsed, and slowly dragged across the water as the bigger fish approached."
"Often the predator would only strike the sucker and let go, probably sensing that something was wrong. We would reel the smaller fish in to find him, or her, often still alive but ripped to shreds."
These videos demonstrates the cruelty of live baiting.
An indepedent expert report for The Royal Society for the Protection of Animals, in Britain, said, "The use of vertebrates as live bait should be banned."