Natural analgesics in goldfish, catfish, lungfish, and trout

Authors: Sneddon, et al
Journal: Brain Research Reviews 46
Year: 2004
Where: University of Liverpool
A nociceptor is a sensory receptor that reacts to potentially damaging stimuli by sending nerve signals to the spinal cord and brain. This process is called nociception.

Many animals have opiate receptors to receive their body’s own natural pain killer, enkephalin, if the need arises. Both opiate receptors and a substance like enkephalin have been found in various species of fish.

"Opiate receptors have been found in fish as well as enkephalin like substances in various brain areas of goldfish, catfish, African lungfish and rainbow trout."

catfish feel pain

Fish Pain