(ANIMAL INTELLIGENCE) AUSTRALIA — Intelligence has often been a trait reserved for animals. However, new evidence suggests that our underwater friends have some tricks – and some tools – up their sleeves. The Tusk fish, a large species of fish found in the Great Barrier Reef, was photographed smashing a shell against a rock on the ocean floor, a clear example of tool use, scientists say. Earlier studies have already proven that fish feel pain. See how this Tusk fish finding is forcing scientists to reevaluate the intelligence and presence of tool use in underwater species. — Global Animal
A Tusk fish uses its mouth to smash a shell on a nearby rock. Photo credit: Scott Gardner

The Sydney Morning Herald, Max Mason

Fish are not generally renowned for their intelligence, but new research suggests they are smarter than we thought.

Tool use, once thought to be exclusive to animals with highly developed brains, has been recorded for the first time by a fish in the wild.

Tusk fish have been photographed appearing to be smashing open cockle shells that were between two and eight millimetres thick.

The pictures were taken by Scott Gardner during a dive at Egg Rock in the Keppel Islands, a protected area of the Great Barrier Reef, in June.

The fish grasps the bivalve in its mouth and swivels its body back and forth, landing alternate blows on the sharp part of the rocks. After several blows, the bivalve cracks open and the fish eats the meat inside.

“The tide is turning on the two-second memory fallacy in academia but it’s taking a lot longer in the general public arena. I can’t tell you how many interviews I’ve done over the years busting this myth,” said Culum Brown, of Macquarie University.

Dr Brown, an expert in behavioural ecology, said the photos force the scientific community to reconsider what tool use is.

“The current terminology is very anthropocentric; perhaps primate biased would be more to the point,” Dr Brown said.

“The laws of physics are not the same underwater especially for an animal that lacks grasping appendages.”

Alison Jones, from the Centre for Environmental Management at Central Queensland University, said: “Even more astounding, and something that the photos do not do justice to, is that the fish is quite large [in the order of 60-80 centimetres] and that the cockle [shell] is also very big and quite thick and dense.

“The nature of shells so thick is to be quite difficult to smash. The bivalve has a muscle that works in a similar fashion to a croc’s mouth: one way is easy and the other takes an extraordinary amount of effort,” Dr Jones said.

Dr Brown said there had been a few recorded cases of tool use by fish in captivity, making this a landmark event for behavioural ecology.

“It’s blatantly obvious to everyone that this fish is using the rock as a tool to access the meat inside, a feat it could never achieve without the tool,” he said.

“Everything about this behaviour says ‘intelligent’, which is not a label your average person would attach to a fish.”

More Sydney Morning Herald: http://www.smh.com.au/environment/animals/wild-fish-show-smashing-skills-in-using-tools-20110914-1k974.html