Have you ever been walking along the beach, seen a little crab scurry under a rock, and wondered: how would that crab react to a really loud Katy Perry song? Because we have! In all seriousness, we spent our lab last week running all sorts of interesting experiments with crabs (yes, including the Katy Perry thing).
The crabs we studied were of the species Hemigrapsus oregonensis. These little critters are common on beaches along the west coast of North America and eat pretty much anything that they can get their claws on: algae, plankton, even smaller crabs. It really is a crab-eat-crab world out there! Our class was split into groups to investigate different aspects of these crabs. For example, one group looked at what factors affect aggression in these crabs by putting them in a series of wrestling-style cage-matches (okay not really, the most aggressive the crabs got was poking each other).
My group decided to investigate whether these crabs would respond to the sound of bird calls. Birds are known to take advantage of low tides by eating exposed crabs. While crabs tend to hide at the first sign of danger, are they able to hear and recognize the sound of their foe? To spice up our experiment, we also measured their response to “Roar”, by Katy Perry.
Unfortunately, we didn’t end up finding any significant trends. It seems that the crabs either don’t count on their hearing, or we needed to do more tests to get a better idea of what was going on. Funnily enough though, several group members noticed that the crabs tended to respond to Katy Perry. While the crabs didn’t care about a mighty seagull roar, apparently they took notice of Katy Perry’s “Roar” (see what I did there?). You’d think that they would be afraid of the music, seeing as it’s probably just a loud noise to them. However, instead of running away from the source of the music, they seemed to run toward it! So, while my group didn’t find any scientifically significant facts, we did find out one important detail: shore crabs appear to be Katy Perry fans. If that’s not hard-hitting science then I don’t know what is.
Interested in learning more about Hemigrapsus oregonensis? Check out this video of one feeding: https://www.youtube.com/watch?v=D2PHyOjIzLI. If you want something a little more science-y, try reading Waldrop’s 2013 paper on crab smelling (https://doi.org/10.1093/chemse/bjt024) or Jensen and Egnotovich’s 2015 paper on crab colouration (https://doi.org/10.1093/czoolo/61.4.729).
BIOL 326: Experimental biology of invertebrates 