Twinspot gobies (Signigobius biocellatus) feeding. These fish are found in sandy lagoons and bays near coral reefs in the Indo-Pacific region. They feed on small invertebrates by sifting mouthfuls of sand. These gobies, which reach lengths of 6.5 centimetres, have two large spots on their dorsal fins that create the illusion the fish are much larger than they are to ward off predators. Photographed off Papua New Guinea.