Do animals think and feel? by Marc Bekoff

Crafty Crayfish? Size Doesn't Matter, or Does It?
Are crayfish capable of deception? We really don't know.

April 20, 2012 by Marc Bekoff, Ph.D. in Animal Emotions

As I've written many times, on-going research continually shows us just how fascinating other animals are. While deception has been discovered in a wide array of animals (see also and) including fish, assassin bugs, and other unlikely candidates, we may now be able to add crayfish to the deception club. It turns out that differences in the size of crayfish claws are not related to strength but it still remains to be seen if this asymmetry is really related to fighting strategies that might include bluff and deceit despite what the headline of this article reports. The enticing headline reads "Size doesn't matter for crayfish's one-two crunch".

So, does size matter? To quote from this essay, "During a clash, a male crayfish sizes up his opponent when deciding whether to fight or flee. Previously, scientists found that stronger, smaller-clawed crayfish would back down from weaker, larger-clawed opponents. So, it was clear that some bluffing occurred between these crustaceans." However, this observation in and of itself does not show that "some bluffing occurred" but it does suggest that this might be the case.

Another quote also goes beyond what we know, at least as far as what I could find in published research reports, but the qualifying words could and suggest keep the door open that bluffing does occur. "This deceptiveness could (my emphasis) help crayfish bluff or trick an opponent during a fight, says study coauthor Robbie Wilson, a biologist at the University of Queensland in Brisbane, Australia. What's more, the findings suggest (my emphasis) that within a species, 'dishonesty occurs in nature more commonly than we expect,' Wilson says."

I only point out the inconsistencies between what is known and the headline because we really don't know whether size does or doesn't matter for members of this species. Indeed, I had a few inquiries about this and then saw the essay when I received my copy of the magazine.

The concluding paragraph is much more in line with what we know and shows clearly that the enticing headline might indeed be a bluff, but it worked for me as did the headline in the shorter essay published in the magazine, "Deception aids crayfish fighters". The last paragraph reads, "If (my emphasis) these crustaceans are deliberately taking advantage of dishonest signals, like using large, weaker claws to pick a fight, it could (my emphasis) tell scientists a lot about how dishonesty develops in nature, says Sophie Mowles, a biologist at the University of Nottingham in England. This work 'could (my emphasis) kind of give us a window into dishonesty and the evolution of bluff and cheating,' Mowles says. Let's hope that future research shows us just what is going on when crayfish encounter one another.

The teaser image can be found here