Ostracods are one of the ocean-living animals which give off light when they are disturbed. Part of the crustacean family and in existence for over a whopping 500 million years old these creatures range from 1mm-32mm in size and can be found on the upper layer of the sea floor.
Where does that light come from eh?
They produce the chemicals luciferin and luciferase, which emit light when mixed together. The process is called bioluminescence, an adaptation that allows animals to be seen in the complete darkness of the deep sea.
The ostracod uses bioluminescence to illuminate when threatened – the light deters predators such as the cardinal fish as they do not want to be seen by other, larger predators. The bright light surprises all predators as they would not be expecting something from such a small creature.
Ostracods also produce light to attract mates.
Most marine bioluminescence is blue, the colour on the visible light spectrum able to travel the furthest through water.
In the deep ocean it is the only light there is.