pygmy shark, Euprotomicrus bispinatus, emitting bioluminescent light in the dark,  view of underside exposed by the light of its own photophores, male, specimen, about 6 inches (16 cm) long - they live in deep water by day (to at least 1,300 ft) and may rise to the surface at night, Kona, Big Island, Hawaii, USA, Pacific Ocean (c)