I came across this in a rock pool here in Looe. Unlike the beadlet anemones (in yesterday's photo) they cannot retract their tentacles. They prefer to be in direct sunlight because they contain algae in their tentacles which need light for photosynthesis. This is a mutual symbiotic relationship - the algae produces sugars and oxygen through photosynthesis which feeds the sea anemone, and the algae uses the carbon dioxide the anemone produces to enable photosynthesis.
Lovely capture with colors, texture and light. My friend has an anemone in his salt water aquarium and it is florescent under the light. It looks like a plant.
