- Peter Parks
- © Image Quest 3-D
With their glassy geometric skeletons, radiolarians are among some of the most beautiful of all plankon. Their skeletons often have arm-like extensions resembling spikes, which increase their surface area and therefore their buoyancy. They exist in a wide variety of shapes including spherical, cone-like and pyramid forms. Different species of radiolarians also exhibit a wide variety of behaviours. They may reproduce sexually or asexually; be filter feeders or predators; or even live in close association with single celled algae.