Sun-Dancing Sea Anemones: A Plant-Like Trick

A sea anemone doing a little dance every day. This is not a fairy tale but a real behavior observed in a species called Anemonia viridis. These sea creatures, also known as snakelocks anemones, have a unique way of facing the sun. They move their tentacles to follow the sun's path, just like plants do. This behavior, called heliotropism or solar tracking, is a way for these creatures to get the most out of the sun's energy. This solar tracking is not just for show. It helps the anemones' tiny algae friends, called endosymbionts, to photosynthesize. Photosynthesis is like the anemones' version of eating. The anemones need sunlight to power this process. The anemones' tentacles point east at sunrise and west at sunset, always chasing the sun. This behavior was only seen in plants before. The anemones' heliotropic dance is driven by specific wavelengths of light that kick-start photosynthesis in their algae friends. Here's where it gets interesting. When the anemones lose their algae friends or when photosynthesis is blocked, they stop their sun dance. This shows that heliotropism is directly linked to the algae's oxygen production. The anemones use this dance to control how much sunlight they get, making sure they get just the right amount. This discovery is a big deal. It shows that even though sea anemones and plants are very different, they can still have similar behaviors. Both use the sun's energy in clever ways to survive. This makes us think about how different organisms can adapt to their environments in surprising ways. So, next time you think about sea anemones, remember they're not just sitting still. They're doing a little sun dance, just like plants.