HRAP Online Encyclopedia

Jellies

Jellies have been floating in oceans across the world for hundreds of millions of years. These adaptable creatures are classified as a type of plankton due to the fact that they drift in ocean currents. True jellies have two primary life stages: the polyp phase where it is attached to a substrate, and the medusa phase where they develop a bell and tentacles. Comb jellies, like the Pacific sea gooseberry, are covered in cilia - little hairs that are fused in rows called combs - that help them swim and reflect light giving off a rainbow appearance. While commonly called jellies, comb jellies are actually not true jellyfish! Jellyfish (along with sea anemones and hydroids) are in the phylum Cnidaria and all contain stinging cells. Comb jellies, on the other hand, are in the phylum Ctenophora and do not sting but instead catch prey through sticking cells. At Haystack Rock it is common to have hundreds of the same species of jelly wash up when currents happen to push a jelly bloom towards shore. Although not all species of jellies in Oregon sting, it is best practice to avoid touching all jellies. Even a dead jelly could still sting!

Reference: Smithsonian Ocean

True Jellies

Comb Jellies