HRAP Online Encyclopedia

Hydroids

Hydroids are an animal related to jellyfish, corals, sea anemones, and other cnidarians. Some hydroids grow as an individual or “solitary” entity, while others form colonies. When in colonies, the original hydroid polyp is attaches to a solid surface and the rest of the colony branches out from there. This structure can give hydroids a plant like appearance, like the feathery ostrich-plume hydroid. Other hydroids look very similar to their jellyfish relatives and float in open ocean. At certain times of year these jelly-like hydroids wash up on Cannon Beach; by-the-wind sailors are often seen in the spring and water jellies are common in the fall.