MATTHEW OLDFIELD / SCIENCE PHOTO LIBRARY MATTHEW OLDFIELD / SCIENCE PHOTO LIBRARY
Fire urchin spines. Close-up of the spines of a fire urchin (Asthenosoma varium), a type of sea urchin. Each spine is tipped with a poison-filled sac (white), used in defence against predators. The spines can inflict severe pain and wounds on humans who accidentally come into contact with the urchin. This urchin is an echinoderm, a relative of the starfish, and possesses the same radial body symmetry (not seen here). Photographed off Kapalai, Malaysia.
Model release not required. Property release not required.