More about our Mantis Shrimp…
We recently began a new demonstration at the Children’s Science Center Lab called, “Creature Feature” where we have introduced animals such as our Peacock Mantis Shrimp, one of the animals that will be on display this summer when we introduce our biology exhibits. During these pop-up demonstrations we teach our guests about the animals and some of the characteristics that make them unique while also covering various STEM topics that relate to the animals.
For example, living things are classified through the field of Taxonomy. Taxonomy distinguishes one living thing from another by looking at their form and structure and use this information to classify them into more and more specific groups. Modern science typically starts classifying by Kingdom and then gets more specific, moving into Phylum, Class, Order, Family, Genus, and then Species as well as subgroups of each.
For mantis shrimp, even though they are called a type of shrimp, they are actually not shrimp at all and are in a completely different taxonomical Order. Shrimp are in the Order Decapoda, which refers to them having 5 pairs of legs with deca meaning 10 and poda meaning foot. Mantis shrimp, on the other hand, have 8 pairs of legs and are in the Order Stomatopoda which means stomach foot, with stomato meaning stomach and poda again meaning foot. Because they begin to diverge in form and structure at this point, they are classified differently.
Mantis shrimp are also very different from other crustaceans because of how they hunt. As a predator, they use what are called their raptorial appendages to either spear or smash their prey. The spearers hunt for soft bodied prey and will impale the animals they are hunting to drag them back into their tunnels to consume. The smashers, like our Peacock Mantis Shrimp here at the Lab, use club like raptorial appendages to smash through the shell or exoskeleton of their prey such as crabs, mollusks, or snails. Both the spearers and the smashers can extend their raptorial appendages at the speed of a .22 caliber bullet being fired from a rifle! Just to give you an idea of how fast this is, a .22 caliber bullet can travel at a speed of between 900-1800 feet per second!
Mantis shrimp also have the most complex eyes in the animal kingdom. Human beings can see 3 basic colors of light, red, green, and blue. All of the other colors we see are combinations of those 3 basic colors. A mantis shrimp, depending on species, can see between 12-16 different types of light which includes infrared and ultraviolet light! It can even use polarized vision and has body parts that can signal to other mantis shrimp using polarized vision to decipher the messages! If you get a chance to see our mantis shrimp up close, you’ll notice that its eyes are on stalks and so it can see all around it in any direction. It also can use each eye independently and has what appear to be 3 different pupils which can each see a different type of light.
How do we support a predator with this much speed? For that, refer back to our last Mantis Shrimp blog entry where we spoke about the nitrogen cycle. In order to house all of the bacteria itself that processes the waste and keeps the water clean, we use what is called live rock. Live rock is very porous rock that allows bacteria to colonize inside of it. The bacteria closest to the outside is aerobic and uses oxygen to help it break down waste in the water. The deeper into the rock you go, however, the less oxygen is available. This is where anaerobic respiration takes place and the bacteria that live here actually break down wastes into methane gas which is then released from the water! This can happen in both the rock and in sand that is deeper than about 5-6”.