Heaps of sea creatures glow to produce light—often in order to see in the murky depths. But scientists have discovered that many bacteria glow for a very strange reason; they want to get eaten.
A team of researchers from the Hebrew University of Jerusalem have discovered that the light emitted by marine bacteria attracts predators—usually zooplankton—which eat them, but aren't able to digest them. Because they don't get digested, the bacteria continue to grow, and over time light up the zooplankton in which they find themselves. In turn, predator fish are attracted to the zooplankton and eat them.
But why the hell is that a good thing for the bacteria? Well, it turns out that, even though the zooplankton are digested, the bacteria safely survive a passage through the fish guts, a finding which is reported in PNAS. Effectively, the bacteria use the concept of being eaten, twice, to hitch a ride and move between different spots in the ocean. "As far as the bacteria are concerned, their access to the fish digestive systems is like reaching ‘paradise' – a safe place, full of nutrients, and also a means of transport into the wide ocean," explained Prof. Genin, one of the researchers. Nature never fails to amaze me. [PNAS via Alpha Galielo ]