Nudibranch, Phyllodesmium poindimiei, photographed by Peter Godfrey-Smith among rocks underwater in Nelson Bay, New South Wales, Australia. It's a small creature, a couple of centimetres long and vividly coloured. Its main body is thin and pale, with dozens of curved projections along its length, which are light purple with white tips and flecks. A couple of straight, pale antennae project forward from its head.