Scientists found that a sea anemone can distinguish helpful bacteria from harmful bacteria without antibodies or immune memory cells

• In the enlarged section, the nematosomes—which are key to the immune system of these invertebrates—are highlighted.
• (Credit: HHU/Nida Kaya)A simple sea anemone (a small plant with white, red, blue or purple flowers that are shaped like cups and have dark centres) can distinguish helpful bacteria from harmful invaders despite lacking antibodies or immune memory cells.