Three quarters of deep-sea animals are bioluminescent

Thanks to advancing camera technology and diligent scientific research, scientists have learned that bioluminescence is not the unusual attribute that we thought it was. Researchers Séverine Martini and Steven H. D. Haddock of the Monterey Bay Aquarium Research Institute (MBARI) recently authored a paper that catalogs its “predominance as an ecological trait.”

The summary: At least three quarters of the deep-sea animals off the coast of Monterey Bay, California can create their own light. The Science Take video above takes a closer look. Some details from Eureka Alert:

Looking through the data, Martini and Haddock were surprised to find that the proportion of glowing to non-glowing animals was pretty similar from the surface all the way down to 4,000 meters. Although the total number of glowing animals decreased with depth (something that had been previously observed), this was apparently due to the fact that there are simply fewer animals of any kind in deeper water.

Even though the proportion of glowing to non-glowing animals was similar at all depths, the researchers found that different groups of animals were responsible for the light produced at different depths. For example, from the sea surface down to 1,500 meters, most of the glowing animals were jellyfish (medusae) or comb jellies (ctenophores). From 1,500 meters to 2,250 meters down, worms were the most abundant glowing animals. Below that, small tadpole-like animals known as larvaceans accounted for about half of the glowing animals observed.

There are excellent sea creature images in The New York Times: The Deep Seas Are Alive With Light. Plus: Haddock’s Bioluminescence Web Page.