Oranged-Dotted Tuskfish Uses Mouth to Carry Tool
Footage of an orange-dotted tuskfish, Choerodon anchorago, using a tool is the subject of a new study published online in the journal Coral Reefs on Sept. 20.
The wrasse uses its pectoral fins to sweep sand away from a buried clam, picks the mollusk up in its mouth, and transports it a considerable distance to a rock where it repeatedly tries to smash it open.
The video was taken in Palau in 2009 by Giacomo Bernardi of the University of California, Santa Cruz.
"What the movie shows is very interesting," Bernard said in a press release. "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."
Tool use in fish has been reported previously, all in wrasse species using rocks to crush shellfish like an anvil.
For example, similar behavior was observed in a black spot tuskfish, Choerodon schoenleinii, on Australia’s Great Barrier Reef, and discussed in an article published online in Coral Reefs on June 24.
Bernardi said he first heard of the phenomenon in 1994, after a colleague spotted a yellowhead wrasse, Halichoeres garnoti, doing the same thing in Florida.
"Wrasses are very inquisitive animals," Bernardi said. "They are all carnivorous, and they are very sensitive to smell and vision."
The wrasse family (Labridae) comprises over 600 species in more than 80 genera, and is one of the largest and most diverse families of marine fish.
Once thought to be unique to humans, tool use has been reported in a variety of species, including chimpanzees, birds, elephants, and dolphins.
Bernardi believes there are probably other examples of fish tool use that are yet to be seen.
"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."
This video shows an orange-dotted tuskfish using its pectoral fins to excavate sand and catch buried prey.
