Before, scientists thought that Sunflower Sea Stars were all killed by a disease, but now it has mysteriously reappeared. What happened?
Pycnopodia helianthoides, also known as the Sunflower Sea Star, is the largest type of the sea star and has the most arms of any sea star species. It may also be the fastest sea star. Sunflower Sea Stars are rare and huge; sometimes it can grow up to a meter wide or an average of a 3-year-old child. The Sunflower Sea Star also has a lot of “rays” which are their tentacles; they can grow as many as 15 to 24 rays that help them to move quickly through the ocean floor. Lastly, The Sunflower Sea Star has about fifteen to twenty-four arms and probably can weigh up to 13.4 pounds. Lastly, its “colors vary from orange to pink, and they have yellow, brown, and purpleish with white spines.”
Sunflower Sea Stars used to be very important in the ocean. They helped to keep the number of sea urchins under control because sea urchins are their main source of food. From 2013 to 2017, many Sunflower Sea Stars died because of a type of bacteria that scientists are now familiar with. This made the number of sea urchins grow. Sea urchins eat kelp, which are like underwater forests. Kelp forests are very important because they give shelter and food to more than 800 more kinds of sea animals such as sharks, fish, and sea otters. Kelp forests also help to take in carbon dioxide, which is good for climate change. Recently, scientists found 18 healthy Sunflower Sea Stars. This has lit up their hope: that these sea stars can help the kelp forests grow back and decrease the amount of overpopulated sea urchins.
Original Article: https://www.bbc.co.uk/newsround/articles/c20y37077e6o
Additional Source: https://www.aquariumofpacific.org/onlinelearningcenter/species/sunflower_sea_star