Snakelocks anemones (Anemonia viridis) fluorescing. This sea anemone has been illuminated by blue light, which excites the green fluorescent protein (GFP) contained in the chlorophyll of its zooxanthellae. Zooxanthellae are symbiotic algae found in the anemone's tissues. The protein absorbs the blue light and emits it as lower-energy green light. The zooxanthellae have a symbiotic relationship with the anemone, producing food through photosynthesis. The anemone also feeds on plankton, small fish, molluscs and crustaceans, which it catches with its long stinging tentacles. It is found in the eastern Atlantic Ocean. These specimens were collected from a rockpool on the Pembrokeshire coast, Wales, UK.