The first video of tool use in fish has been published by a scientist from the University of California.
The video below, taken in Palau in 2009, features an Orange-dotted tuskfish (Choerodon anchorage) digging up a clam then swimming quite a distance to find a rock and then repeatedly throwing the clam against it to crush it.
Professor Giacomo Bernardi said of the video: "What the movie shows is very interesting. The animal excavates sand to get the shell out, then swims for a long time to find an appropriate area where it can crack the shell. It requires a lot of forward thinking, because there are a number of steps involved. For a fish, it's a pretty big deal."
This is not the first time that tool use has been observed in with a report in Coral Reefs journal back in June on black spot tusk fish smashing open shells on an anvil to access the meat inside.
Bernardi said he first heard of the phenomenon in 1994, when a colleague (James Coyer) observed a Yellowhead wrasse in Florida doing the same thing. Similar behaviour was also reported in a Sixbar wrasse in an aquarium setting.
"Wrasses are very inquisitive animals," Bernardi said. "They are all carnivorous, and they are very sensitive to smell and vision."
Bernardi, who studies fish genetics, said there may be other examples of tool use in fish that have not yet been observed. "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."
Tool use is conventionally seen as a sign of intelligence and was once considered unique to humans until Jane Goodall observed tool use in chimpanzees. Since then a wide range of animals have been observed using tools but this is the first time this behaviour has ever been videoed in fish.
For more information see the paper: G. Bernardi. The use of tools by wrasses (Labridae).Coral Reefs, 2011; DOI:
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