The tube-dwelling anemone is an animal with long tentacles that can retreat into a protective tube, which extends deep into the ground. You can find Tube Anemones on ocean bottoms from Alaska to Baja California. This anemone is a filter feeder and will also eat small fish that it can catch with its stinging tentacles. The Tube Anemone is also a favorite food for the Nudibranch. 
Most Tube Anemones have either 64 or 128 tentacles and they have radial symmetry. The number of tentacles depends on the species but most have only 128 tentacles. The Tube-dwelling Anemones that are smaller and live in colder water are mostly the ones with 64 tentacles. There are stinging cells on the tentacles and the colors of these tentacles can be a range from purple, pink, green, blue, yellow, and brown.  This animal also makes a long slime covered tube that it can pull itself into when it feels threatened. This tube can extend about a meter and is buried into the mud.
The way that the Tube-dwelling anemones reproduce is by releasing eggs into the water that then develop into larvae and float away. About 99% of the eggs end up being eaten by fish or animals or die before reaching the mature stage. 
Tube Anemones are usually found on muddy and sandy ocean bottoms in the Puget Sound region of North America and cover a range from Alaska to Baja California. This creature is not an anemone but is really a coral and makes a tube to live in. When threatened, the Tube-dwelling Anemone pulls itself into its tube for protection from predators. This species grows to about 12” and is a favorite food for the Nudibranch.
The Nudibranch will slowly sneak up on the Tube Anemone and then will quickly dive into the Tube Anemone's Tube. At this point, the Tube Anemone will try and pull its tentacles into its protective tube, but by then it's usually to late and the Nudibranch will already be deep inside of the tube and start to eat the Tube-dwelling Anemone. 
- NetPets http://www.netpets.com/fish/reference/reefref/ceranemone5.html
- Tube Anemone http://www.boydski.com/diving/photos/tubeanemone.htm
- Chup Point http://swash.seaotter.com/marine////html/chuppoint.html