Dr Robbie Wilson, a researcher with Australia’s University of Queensland, has found that crayfish with bigger claws can trick their opponents into believing they are also stronger fighters.
"What we found was that many of the crayfish were winning fights through intimidation alone, and were actually weak-clawed individuals," he said.
Crayfish, also known as crawdads, yabbies or marrons, are heavy bodied freshwater crustaceans, visibly different from the small lobster, to which they are related, by large pincer like forelegs.
Australia is home to three of the largest freshwater crayfish in the world and also the smallest.
Dr Wilson and his colleagues found that claw size was not an accurate indicator of claw strength. This was a surprise, he said, as dishonesty is not commonly seen in animals.
"The roar of a lion, the bark of a dog, or even the fairing fins of a male Siamese fighting fish are all signals between competing individuals," he said.
"These signals are expected, by theory, to be an honest indicator of how strong that individual is and how it could inflict injuries on opponents.
"We found that dishonest signals can occur and in very high frequencies in nature, which is very cool and very surprising."
While having big ‘guns’ may have its advantages, Dr Wilson said there is also a downside, with the larger claws proving cumbersome when trying to swim away from predators.
"Whether they are strong or weak, all crayfish with larger claws must pay this extra cost," Dr Wilson said.
