Light emitting organs on the underside of velvet belly lantern sharks help camouflage them via bioluminescent counterillumination.

“Many midwater animals emit ventral light to hide their silhouette in the
water column. This phenomenon known as counterillumination typically
requires fine control over light emission since it needs a luminescence
that closely matches the properties of downwelling light (intensity,
angular distribution and wavelength). Here we provide evidence that,
although lacking complex structures of counterilluminating animals, the
deepwater luminescent shark Etmopterus spinax could, in Norwegian
fjords, efficiently cloak its silhouette from downwelling ambient light
to remain hidden from predator and prey. This represents the first
experimentally tested function of luminescence in a shark and
illustrates how evolution can take different routes to converge on
identical complex behavior.” (Claes et al. 2010:28)

Last Updated September 14, 2016