David Attenborough's Life That Glows (2016)
Dinoflagellates, ostracods, brittle stars, emit light to protect themselves. Their light is, as Attenborough puts it, a kind of burglar alarm. Creatures can also use bioluminescence to attract mates, such as fireflies and ostracods.
Creatures can also use light to prey on others. Luminous larvae in termite mounds in Brazil or in caves in Tasmania use light to attract prey.
For other species, the reason the animal glows has yet to be determined. For instance, the exact reason a particular type of earthworm in France is unknown.
Most living lights can be found in the ocean's twilight zone. Vampire squid, viper fish, and dragonfish are a few examples of the myriad life forms found in the mesopelagic zone.
David Attenborough's Living Light proves the world, especially the oceans, is full of luminous life forms whose secrets we are just beginning to understand. He explains, too, the technical difficulties of finding and recording their light frequencies.
