Dr. Sylvia Earle, one of the world's leading marine biologists, said, "I never eat anyone I know personally. I wouldn't deliberately eat a grouper any more than I'd eat a cocker spaniel. They're so good-natured, so curious. You know, fish are sensitive, they have personalities, they hurt when they're wounded."
Many people have never stopped to think about it, but fish are smart, interesting animals with their own unique personalities — just like the dogs and cats we share our homes with. Did you know that fish can learn to avoid nets by watching other fish in their group and that they can recognize individual "shoal mates"? Some fish gather information by eavesdropping on others, and some — such as the South African fish who lay eggs on leaves so that they can carry them to a safe place — even use tools.
Scientists are starting to learn more and more about our finned friends, and their discoveries are fascinating:
• A recent issue of Fish and Fisheries, devoted to learning, cited more than 500 research papers on fish intelligence, proving that fish are smart, that they can use tools, and that they have impressive long-term memories and sophisticated social structures. The introductory chapter said that fish are "steeped in social intelligence, pursuing Machiavellian strategies of manipulation, punishment and reconciliation … exhibiting stable cultural traditions and cooperating to inspect predators and catch food."
• Culum Brown, a
University of Edinburgh biologist who is studying the evolution of cognition in fish, says, "Fish are more intelligent than they appear. In many areas, such as memory, their cognitive powers match or exceed those of 'higher' vertebrates, including non-human primates." Their long-term memories help fish keep track of complex social relationships. Their spatial memory — "equal in all respects to any other vertebrate" — allows them to create cognitive maps that guide them through their watery homes, using cues such as polarized light, sounds, smells, and visual landmarks.
• Dr. Phil Gee, a psychologist from the
University of Plymouth, says that fish can tell what time of day it is, and he trained fish to collect food by pressing a lever at specific times. He says "fish have a memory span of at least three months," and they "are probably able to adapt to changes in their circumstances, like any other small animals and birds."
• A scientific review presented to the Australian Veterinary Association completely disproved the old myth that goldfish have three-second memories; instead, the veterinarians found that goldfish have impressive memories and problem-solving abilities. One of the researchers said that after conducting the review, they wanted “to get the message out to vets to start looking more closely at fish and considering their welfare like they do other animals.”
—The Sunday Times,
May 28, 2006
• "Australian crimson spotted rainbowfish, which learnt to escape from a net in their tank, remembered how they did it 11 months later. This is equivalent to a human recalling a lesson learnt 40 years ago."
— Sunday Telegraph,
Oct. 3, 2004