Size Over 6 "
Habitat
This is one sea anemone one should be aware of, as its stings have been known to affect humans.
Description & ID Features
This anemone cannot retract its tentacles and therefore limitted to rock pools, as if it was exposed to the air it would be prone to dessicate and die.Snake Locks, exhibits two colour forms brown or green with purple tipped tentacles.
The Green Form exhibits a Symbiosis, the green pigment coming from algae zoochlorellae. This is a mutual symbiotic relationship , beneficial for both algae and anemone..The Anemone also seeks well lit areas where the algae can efficiently photosynthesis within the protection of the stinging anemone. The brown forms are maybe those deficient in algae.
Habitat Present mainly in the intertidal especially in pools from mid-tide downwards but not extending far into the sublittoral. However, frequently present, often in large numbers on the leaves of seagrass
By Pline (Own work) [GFDL or CC BY-SA 3.0], via Wikimedia Commons