Comb Jellyfish

Comb Jellyfish (Pleurobrachia sp.)

Rows of comb plates containing little “oars” for locomotion
 
Neon lights refracting off pulsating cilia

One of the first creatures you will see when entering the aquarium are the beautiful Comb Jellies…they are called jellies, but they are actually not a jellyfish! All other jellies in the Salish Sea are from the phylum Cnidaria, but comb jellies are Ctenophores (Greek for “comb” and “to bear”). Comb jellies are egg-shaped and quite small, about 1.5 cm in length, and have two long tentacles that can reach a length of 15 cm that they use like fishing poles.
These guys are named after the  eight comb plates running in rows along their body, which contain thousands of little cilia (hair-like structures) paddles that help the jelly move through the water like tiny oars. Many types of microscopic organisms such as bacteria use cilia for locomotion, but the comb jelly is the largest creature known to do so. It is cool to watch these little guys, because these paddles do not always move at the same time or beat in unison, depending on what direction they want to go (unlike regular jellyfish who pulsate their bells).
Why are these guys so cool looking?? In the right light, they give off an awesome neon rainbow effect, because their beating cilia can refract light (not to be confused with bioluminescence!). You might think this magical and colourful movement of cilia would require a brain, but comb jellies being brain-less, rely on a network of neurons and a special navigational tool called a statolith.
Another difference between the comb jelly and other true jellyfish is the way they capture their prey. Jellyfish use stinging cells called nematocysts that work like tiny harpoons filled with venom, whereas, the comb jelly uses its non-stinging tentacles that contain glue-like cells called colloblasts that work like a sticky fly trap to capture small planktonic animals.
Next time you go to the shoreline, have a look for a flash of rainbow in the waters and you might have found a comb jelly!!

http://www.pugetsound.edu/academics/academic-resources/slater-museum/exhibits/marine-panel/comb-jelly/

https://www.sanjuansafaris.com/whale-report/jellyfish-salish-sea-0

https://edgeofthesalishsea.wordpress.com/2015/08/04/ctenophores-the-comb-bearers/