Those who deal with animal rights should recognize fish as creatures worthy of protection as well, according to a scientific survey published last week dealing with animal cognition.

According to the study conducted by Australian researcher Culum Brown in the Animal Cognition journal, in many ways fish have cognitive capacity that is no less than that of many vertebrates, and can feel pain similar to the way many mammals do.

In “Fish intelligence, sentience and ethics,” Brown surveyed and analyzed numerous studies about fish behavior and their sensory abilities, and compared them to various vertebrate species – from birds to mammals. He primarily referenced indices of awareness and cognitive abilities, because “the perception of an animal’s intelligence often drives our decision whether or not to include them in our moral circle,” he wrote.

Brown found that fish have senses that are as developed as those of many mammals, including sophisticated senses of vision and smell, and that many species of fish have memories. In one experiment, fish were trained to flee danger through a specific hole in a net. A year later, they remembered what they had learned, successfully fleeing through the same hole.

Fish live in developed social systems, can recognize other individuals, and can learn from one another and even pass on “cultural traditions” to the next generation – such as the best places to find food, the study finds. They form partnerships, sometimes with other species – for example, to hunt jointly for food. They can build nests and hiding places by building small mounds of stones.

Having developed-cognitive abilities is a prerequisite for animals to feel pain that is not merely a reflex, but expresses distress that has a conscious or emotional dimension. This is what has traditionally served as the basis for legislation whose aim is to prevent animal pain and suffering.

Brown is convinced that fish have the ability to feel such pain. One proof he offers is that when fish are exposed to circumstances that cause pain, they are distracted from their other activities and don’t pay heed to dangers that are meant to stimulate a flight response. What’s more, fish brains have mechanisms similar to those of vertebrates who feel pain, among them human beings.

“A review of the evidence for pain perception strongly suggests that fish experience pain in a manner similar to the rest of the vertebrates,” Brown wrote. “Although scientists cannot provide a definitive answer on the level of consciousness for any nonhuman vertebrate, the extensive evidence of fish behavioral and cognitive sophistication and pain perception suggests that best practice would be to lend fish the same level of protection as any other vertebrate.”