Scientists have discovered that fish do not feel pain as they do not have a brain system or enough sensory receptors in the nerve cells to experience suffering. Fish do not even suffer when they are hooked and fighting for their lives, according to research by an international team. While fish may struggle to get free, scientists say this does not mean they are in pain. Instead, they show “little effect” from injuries and toxins that would leave humans in agony, the Daily Mail reported. Researchers inserted needles into the jaws of rainbow trout.

“In spite of large injections of acid or bee venom, that would cause severe pain to a human, the trout showed remarkably little effect,” Jim Rose, professor of zoology and physiology at the University of Wisconsin, who led the project, said.

Fish resumed normal activity within minutes of surgry, as well as after being caught and released back into the water.