The velvet belly lanternsharks look pretty unique.
Earlier this year a new species of deep water shark, Etmopterus lailae, was discovered in waters surrounding the Northwestern Hawaiian Islands in the Pacific Ocean.
Measurements of external features, teeth, vertebrae and intestines, along with specific external markings and patterns confirmed that it was indeed a new species – a member of the lanternshark family. Lanternsharks (Etmopteridae) are one of the most species-rich shark genera, with approximately 38 known species, 11 of which have been described since 2002.
The lanternsharks are one of two deep sea shark families to possess the ability to bioluminesce – in other words, they are able to glow in the dark. The other shark family with the ability to do this are the kitefin sharks (Dalatiidae). This family houses the infamous cookie cutter shark, which was known for its impressive ability to disable US Navy submarines in the 70s and 80s, by testing how the electrical cables and rubber sonar domes rated on a culinary scale (Johnson 1978). Imagine being the officer who had to report back about how the submarines were defeated by a particularly voracious … 22 inch (56cm) shark!
Bioluminescence is the emission of light as a result of a biochemical reaction. In contrast to fluorescence and phosphorescence, bioluminescenct reactions do not require the initial absorption of sunlight or other electromagnetic radiation by a molecule or pigment to emit light.
Most fish bioluminesce by using their light organs (photophores) in one of two ways: harnessing the light produced by symbiotic bacteria or producing their own light through chemical reactions. However, shark luminescence works in a different way.
The organisation of the photophores strongly suggests that they are involved in varied behaviours, including anti-predatory response (camouflage) and intraspecies communication.