The sixbar wrasse, Thalassoma hardwicke, has been observed breaking its food up into pieces by smashing it against rocks. (Leonard Low/Wikimedia Commons)

Fish probably use tools much more than we realize, according to new research from Australia.

Originally, tool use was believed to be a trait only exhibited by humans, but now scientists have documented primates, dolphins, and several bird species using tools for various tasks.

Despite lacking hands and the difficulties of manipulating tools underwater, fish have also been found to exhibit various innovative tool use behaviors to achieve their goals.

“Fishes lack grasping limbs and operate underwater where there are clear constraints with respect to the physics of tool use that differ dramatically from the terrestrial environment,” explains behavioral biologist Culum Brown at Macquarie University in his study abstract.

Brown recently documented tool use in a tusk fish using an object with its mouth to smash open shells.

“There is an increasing body of evidence that suggests that fish have been largely underestimated in terms of their abilities,” Brown said in a press release.

Similarly, many other wrasse species use anvils to smash open shellfish and other awkward prey.

“We now have fantastic proof of these intelligent fish at work using tools to access prey that they would otherwise miss out on,” Brown said.

Brown believes that the way some fish manipulate their watery environment meets the common definition of tool use.

“Archerfish squirt water from their mouths to dislodge terrestrial prey items above the surface and trigger fish blow water streams to turn sea urchins over, to access their more vulnerable side,” he said. “Both documented examples have all the hallmarks of tool use and are probably cognitively demanding.”

Fish are rarely studied as intensively as birds and mammals, and there may be further examples awaiting discovery.

“We really need to spend more time looking underwater to find out just how common tool use is in marine fishes,” Brown concluded. “It is likely that further examples will continue to be unveiled.”

The study was published online in the journal Fish and Fisheries on Nov. 24.