What are Cnidarians?

What are Cnidarians?

“Cnidarians” isn’t a word most people would associate with animals, yet almost everyone has heard of at least one organism from this stinging group, like Jellyfish and Sea Anemones!  There are all kinds of other cool organisms in the Cnidarian family that you can start to explore in the Cnidarian Center of the Kids’ Zone.  

Cnidarians are a super unique group of animals that have been around for more than 500 million years! That is such a long time! There are lots of different species of Cnidarians spread out between the four main groups: Anthozoa, Scyphozoa, Cubozoa, and Hydrozoa.  However, they are all defined by their highly specialized stinging cells called  Nematocytes.  These amazing cells act like harpoons and shoot barbed arrows to help capture and anchor their prey. These specialized cells are also called Cnidocyte and are used by all species of Cnidarians.

All Cnidarians are aquatic and spend their entire lives in water. Cnidarians are mostly marine creatures, but there are certain species found in freshwater. There are even a few burrowing species of Cnidarians. You can learn more about different habitats for all organisms in our Habitats and Biomes center.

Cnidarians all look different, but they all have radial symmetry, meaning they are all generally shaped like a circle. There are two different body styles of the Cnidarians: Polypoid and Medusae. Polypoid Cnidarians form giant colonies of organisms that we refer to as corals and anemones. Medusae are free swimming Cnidarians like the jellyfish and box jellyfish.

To learn more about the Cnidarians, be sure to check out the other Cnidarian center tiles like the Anthozoa Center or the Scyphozoa Center. You can even learn about awesome things like the mesoglea and the nematocytes!   See you next time Defenders!