Anemones and their algal partners in extreme environments

Hi there! My name is Maria Ruggeri. I am a 5th-year PhD candidate at the University of Southern California in Carly Kenkel’s lab and this summer’s Victoria J Bertics Wrigley Fellow! I study intertidal sea anemones to identify strategies we can use to save coral reefs. Continue reading below to learn how!

Both corals and sea anemones are part animal, and part plant! Anemones and their coral cousins form a life-long partnership with marine algae, which live inside of their tentacles and give the animals their brown/green color. The algae, like other plants, photosynthesize to produce sugars, which the animal host can eat. In return for food, the host give the algae a safe place to live with lots of light. However, when the animal host is stressed out, such as on a really hot day, it will kick its algae friends out (I’m sure most of us can relate ).

Corals are very sensitive to temperature and will die if they go too long without their algae friends — this is why climate change is the main threat to coral reefs worldwide!! Unlike corals, some anemones and their algae can survive EXTREME temperatures during low tide. So how do they survive when a coral would die?? One hypothesis could be that the anemones are resilient — they kick out their algae on hot days, but they recover their algae when temperatures cool down. Another hypothesis is that the anemones are resistant to high temperatures – meaning they are not stressed by high temperatures at all and let the algae stay!

This summer, I sampled anemone tentacles (don’t worry, their tentacles grow back ) every day for one-week during a natural tidal cycle to see whether anemones were resilient or resistant to high temperatures. This allowed me to capture very hot days, followed by cooler, less stressful days when the anemone would have had a chance to recover.