Tool use was once considered an exclusive hallmark of human intelligence and ingenuity. Then, in the 1960s Dr. Jane Goodall stunned the world with the revelation that other primates (in this instance chimpanzees) also use tools. Since then, numerous scientists have documented tool use among other mammals, such as elephants and dolphins, and even among birds. Now Giacomo Bernardi, professor of ecology and evolutionary biology at the University of California, Santa Cruz, has documented tool use by a fish.

Published in the journal, Coral Reefs, the video (below) shows an orange-dotted tuskfish - a type of Wrasse - digging a clam out of the sand, carrying it in its mouth and swimming some distance to an appropriate location, before repeatedly flinging the bivalve against a reef rock to break its hard shell and expose the tasty flesh within. Bernardi seemed impressed by the determined fish's behavior. "It requires a lot of forward thinking, because there are a number of steps involved," said Bernardi. "For a fish, it's a pretty big deal."

Bernardi believes this is the first direct video evidence of such behavior among fish, although he notes that this type of behavior has been reported anecdotally before, and some photographs have surfaced showing similar activity. Most recently, photographs of similar behavior by a tuskfish on Australia's Great Barrier Reef appeared in the June issue of Coral Reefs. Interestingly, the previous reports have all involved various species of wrasses. "Wrasses are very inquisitive animals," Bernardi said. "They are all carnivorous, and they are very sensitive to smell and vision."

Wrasses are also one of the largest and most diverse groups of marine fish. Bernardi speculates that this tool-using behavior may be more common than scientists might have suspected. "We don't spend that much time underwater observing fishes," he said. "It may be that all wrasses do this. It happens really quickly, so it would be easy to miss."