How to Collect Stomatopods

Animals live in some crazy places. Up high on mountains, down in the depths of the sea, underneath antarctic ice. Life, through evolution, has found a way to live in just about every extreme environment on Earth (and possibly beyond). To study these animals, often biologists have to go to some of these crazy places, so biologists are also hikers, mountain climbers, sailors, and divers.

The animals that my friend Molly studies are stomatopods, or mantis shrimp. They come in a lot of different sizes and colors and live in different places in the ocean, but the species that she studies lives in the sandy-bottoms of the back reef on tropical islands. The sandy-colored males and pink females live in burrows that they dig that are shaped like the letter "U" and up to 12 inches deep. To study them, she needs to take them back to California, and to do that, we need to dig them up. Since they live under the water, we do this SCUBA diving.

SCUBA stands for "Self-Contained Underwater Breathing Apparatus," and is a way for people to spend some time under the water and sometimes go very deep to study and enjoy marine life. You saw all the equipment for diving in the first Packing for Moorea video. Here we will be using it to collect Molly's stomatopods!

Step 1: Find their burrows

Once you've geared up and jumped in the water, you need to find a stomatopod burrow. Stomatopods like to stalk their prey from the entrances of their burrow, and their little white eyes look just like two more sand grains on the surface. These holes are flush with the surface and look almost like two paper-punch holes that sit about 4-8 inches apart. Sometimes, there are a lot of holes and you're not sure which ones match up, so you have to make a guess. Here is a picture of a stomatopod burrow:



Step 2: Dig and dig and dig...

The best way to dig up a stomatopod burrow is to start by digging on either sides of the two holes so that the sand falls away from the burrow itself. That way, you can follow the burrow holes as you dig and tell when you've reached the bottom of the burrow (without the stomatopods getting scared and swimming away). Here is a burrow that I've partially dug up:



You have to keep digging until you see the burrow bend into a U or otherwise, you won't get the whole things, and your stomatopods will get away!

Step 3: Put the burrow in a plastic bag

The way we collect and transport stomatopods back to the lab is in a plastic zipping bag, like your parents might use to store vegetables or meat in the freezer. When you get to the bottom of the burrow, you take your shovel and scoop as much of the sand in the bottom of the hole (hopefully this includes the burrow) into the bag and zip it shut as fast as you can. I'm not always quick enough, and so sometimes I have to chase the stomatopods around and try to scoop them in the bag if they get out. Here is a bag full of a family of stomatopods (a male, a female and eggs):



Step 4: Transfer back to lab and put into cups

When we are done diving, we bring all the bags full of sand, water, and stomatopods up on the boat and drive back to the lab. From there, Molly has to sort out and catch the stomatopods with a turkey baster and put them in cups with some sand. They quickly dig new burrows. When it's time to fly back to Berkeley, she'll put them in plastic tubes and make sure that they have new air on the way back home. They do really well like this, even though it seems like the would be pretty cramped in a tube!

Molly and I both think this is pretty fun work!