Pacifists or pugilists?

“They’re very gentle.”

I met Silvia Sintoni in front of her poster at the International Congress of Neuroethology in Vancouver in 2007. I was very interested and excited to talk to someone working with the all-female marbled crayfish, Marmorkrebs. I talked with her about how they housed the animals in her labs. She told me they kept most of their animals communally, which surprised me slightly, because I thought of crayfish as aggressive.

Crayfish fighting has been the subject of much research since the 1950s. And when I kept Louisiana red swamp crayfish (Procambarus clarkii) together, there would often be murders, particularly when one molted.

Silvia assured me that these animals were not terribly aggressive – though I wondered if there might be a little projection of traditional human female characteristics onto the crayfish.

But another paper also mentioned low levels of aggression in Marmorkrebs, basically as an anecdote. And when I got my first Marmorkrebs in my lab to start the aquarium, on one of the first days, I came in to find three or four of the adults all hiding under the same piece of clay pot – which was not something I had seen other crayfish do!



After a few days, though, I too k the picture above of some fighting in my new tank. The girls were not completely averse to fighting!

It was just a natural and obvious thing to see if people’s impression matched up to reality. Were these marbled crayfish less aggressive than other crayfish species?

This became the project of my co-author Stef (more formally Stephanie A. Jimenez), seen here presenting some early results at the 2009 Ecological Society of America meeting.



We explored a lot of ideas that didn’t quite make it into the final paper. In particular, Stef ran one fairly lengthy experiment that we were never quite sure what to do with, because it failed to replicate a result from another lab. And I’ve learned from experience those are... problematic... to get published.

As it was, this paper didn’t have the easiest time finding a home. But I’m pleased it did find a home and hope you enjoy it.

Massive thanks

To all my students this year, who helped me have one of the best years of my career:

Sakshi, Stef, Unnam (all with papers published or in press), Nadia, Sandra (both with papers in review), Jessica, Karina, and Samantha (no papers yet, but watch out editors! They could be coming your way in 2011!).

Thanks for your hard work, guys.

Reference

Jimenez SA, Faulkes Z. 2011. Can the parthenogenetic marbled crayfish Marmorkrebs compete with other crayfish species in fights? Journal of Ethology 29(1): 115-120. http://dx.doi.org/10.1007/s10164-010-0232-2

Other stories behind the papers

Crayfish zero
Crustacean nociception