Mantis Shrimp Rock!

Today, as some of you already know, I started a project on Microryza. Microryza is a company that helps scientists raise money to complete their research. (You should check out my project!)

Anyway, in the spirit of this research I decided to write a post sharing my love for mantis shrimp. Because they are freakin’ awesome. First things first, mantis shrimp are actually not a shrimp (or a mantis). Although they do kind of look like a cross between the two, they are in their own crustacean group.


Some species look especially like praying mantises when capturing their food, which is where the name came from.


However, if you think that looks scary, let me tell you about the ‘smashers’. Instead of spearing their prey (as above), they punch it. And when they punch, they do it properly. It is the fastest punch in the animal kingdom, which is pretty amazing since it’s in water, and creates a cavitation bubble. Cavitation is when a small bubble forms in a liquid due to extreme forces. When this bubble bursts the prey is damaged. So the prey not only gets hit by the ‘raptorial appendage’ (what a bad-ass name!), it also gets a second blow from the cavitation bubble. The prey doesn’t stand a chance!

Besides these ninja-like features, they also have the most complex visual system known to man! They have up to 16 visual pigments (humans have three), can see UV, infrared and polarised light (as well as the light we can see), can perceive depth with only one eye and can move each eye independently! It’s impossible to even imagine what the world looks like to a mantis shrimp.

So next time you go out snorkelling or diving on a coral reef, look out for a mantis shrimp. These bright and colourful critters are awesome, which I’m guessing is why so many people want them as aquarium pets. And there is still so much more to learn about these animals and how they behave in the wild!

Post Fieldwork Round-Up

Video copyright Amanda Franklin, not to be used without permission

I just realised that I never wrote a blog post about my fieldwork in Belize. I got too excited by actually being punched by a mantis shrimp to share the other tales of my trip.  (It is pretty exciting to be punched by the animal with the fastest punch in the world, even if it was only a small one).

Even though that one shrimp managed to get me, I did find and catch 30 shrimp in the two weeks I was there. I must say, I think I’m pretty good at finding them now! My method involves sticking a probe into any cavities in coral rubble that look ideal for a mantis shrimp, and, if one is in there, it can’t resist punching the probe. Wah lah! I have a new shrimp to investigate behaviour.

Once I had enough male and female shrimp, I paired them up and watched their interactions in a tub outside (you’ve got to keep the lighting natural!). It was very interesting! They would display, punch, try to take over the cavity from the occupying shrimp and one pair actually mated! However, I do think the interactions would be more realistic if I did the experiments in the ocean (which is my plan for the next field trip!). This is because the lighting will be more realistic and the concentration of chemical cues wouldn’t be too high.

I also found several large mantis shrimps in burrows that they dug in the sand in shallow water (<30cm). I managed to take some video footage of one making a sand cap to close off its burrow.  Check it out above. What you’ll see is a shrimp using its maxillipeds and some sort of sticky saliva to stick the sand grains together over the burrow opening. The whole process lasted about 15 minutes, so I’ve just shown you the start and the end here.