Biologists discover mystery marine larvae

Scientists have discovered a new set of microscopic creatures, the larva of animals which look different when they are an adult. The little-known microbes, called phoronids, are horseshoe worms. The adults anchor in sediment or to rocks or coral, creating a tube of chitin to save their soft bodies, while their heads have active tentacles that constantly wave in the current to strain small particles of food from the water.