Anthopleura xanthogrammica “Giant Green Anemone” Anthozoa

Oregon Coast Aquarium, Newport, OR
June 12, 2015
Robert Niese


These anemones can grow up to a foot tall and a foot across! They’re abundant on rocky and sandy shores throughout the north-eastern Pacific (from Alaska to Panama). They tend to occur lower in the intertidal zone than their little, pink counterparts (A. elegantissima). The Giant Green Anemone primarily consumes dislodged mussels, crabs, small fish, and urchins, but has been recorded consuming larger animals including baby birds! It’s primary predators are leather stars, snails, and the shaggy mouse nudibranch.

Anthopleura elegantissima “Aggregating Anemone” Anthozoa

Olympic National Park, WA
June 1, 2013
Robert Niese

A very common intertidal resident here in the Puget Sound and on the open coast. If it’s big and green, it’s Anthopleura xanthogrammica. If it’s white and has very fine tentacles (usually subtidal, not intertidal) then it’s Metridium. Now you can identify 90% of the anemones you find in your backyard!