Column blotched with red and green, but can also be any combination of olive, brown, yellow, and red. The column is dotted with small tubercles.
Alaska to Southern California.
Alaska to Southern California.
Urticina crassicornis is often found hanging or below the underside of boulders. It can also be seen attached to rocks, docks, and other solid substrates in the intertidal and shallow subtidal areas.
Uncommon.
This is one of the larger anemones on the Central Coast of British Columbia. It has small tubercles on the column wall but lacks an acontia. The column varies in color from blotches red and green to olive, yellow, brownish, or red. The tentacles are cross-banded and end with a blunt tip. There are no radiating white stripes across the oral disk. Can be seen stretched out and drooping from the rock at low tide.
A large anemone that lacks an acontia and has no radiating white stripes across the oral disk. Varies in colors including blotches of red and green to olive, brownish, or red.
Column diameter: 20 cm
Height: 30 cm
The candy-striped shrimp Lebbeus grandimanus has a commensal relationship with the Christmas anemone. It appears to be unaffected by the anemone’s sting, so it is able to live on or around the anemone gaining protection and food scraps.
There is some confusion between Urticina crassicornis, Urticina piscivora, and a species described by Sanamyan and Sanamyan (2006) as Urticina grebelnyi. Let’s start with a species most of us call Urticina piscivora, easily identified by a smooth red column, lacking tubercles, vesicles, or verrucae. This species with its very smooth, red column is—according to the Sanamyans—Urticina crassicornis. But most people—incorrectly—call it U. piscivora.
So, if the smooth red column is U. crassicornis, then which species has a green-red mottled column? Most web sites ID that as U. crassicornis, but it is not, according to the Sanamyans. The red and green mottled column belongs to Urticina grebelneyi.
And where does that leave Urticina piscivora? Apparently it does not occur along the west coast of the US!
To recap, according to the Sanamyans and their peer-reviewed publications:
Smooth red column = Urticina crassicornis (not U. piscivora)
Mottled red-green column = Urticina grebelneyi (not U. crassicornis)
Predators are unknown.
Prey consumed include crabs, urchins, mussels, gastropods, chitons, barnacles, and fish. May also feed on stranded jellyfish.
Omnivorous, opportunistic, sessile predator. Food is caught within the tentacles which then moves the prey towards the oral disc. On the tips of their tentacles are nematocysts which are stinging cells that release neurotoxins. These neurotoxins serve to paralyze the prey.
Cowles, D. (2005). Urticina crassicornis (O. F. Muller, 1776). https://inverts.wallawalla.edu/Cnidaria/Class-Anthozoa/Subclass_Zoantharia/Order_Actiniaria/Urticina_crassicornis.html. Accessed [22 June 2020].
Fretwell, K. and Starzomski, B. (2013). Painted anemone. Biodiversity of the Central Coast. https://www.centralcoastbiodiversity.org/painted-anemone-bull-urticina-crassicornis.html. Accessed [22 June 2020].
Sanamyan NP, Sanamyan KE, and McDaniel N. 2013. Two new shallow water sea anemones of the family Actiniidae (Cnidaria: Anthozoa: Actinaria) from British Columbia (NE Pacific). Invertebrate Zoology 10(2):199-216
Sanamyan NP, Sanamyan KE. 2006. The genera Urticina and Cribrinopsis (Anthozoa: Actiniaria) from the northâ€western Pacific. Journal of Natural History, 40:7-8, 359-393, DOI: 10.1080/00222930600703532