Invertebrates common to the Pacific Northwest
Here are some of the more common Invertebrates that you will see on your dives in the Pacific Northwest. They are beautifully colored, but be sure to bring your own light. It's dark and drab down there without a dive light.
Lion's Mane Jellyfish
These rather painful creatures materialize out of the gloom when you least expect them. Tentacles and nematocysts will live for a long time after breaking off from the main body, and will raise painful welts on exposed skin.
Vinegar works very well to counteract jellyfish stings.
If you are trying to identify an unknown critter, take a look at the Northwest Diver Creature Feature. Several of my photos are published as part of this database of Northwest Creatures. It is a great resource for Northwest Divers.