The glowing sea fireflies of Okayama, Japan

From insects and mushrooms to deep-sea predators and phytoplankton, bioluminescence is found throughout the world. One of the most well-known examples are fireflies, but did you know there's a creature known as a sea firefly? These striking ostracod crustaceans inhabit the waters surrounding Japan, where they are known as "umi-hotaru." Although they only measure a mere 3 millimeters long, they produce a brilliant blue-colored glow in response to physical stimulus.

The pair are based in Okayama, Japan, an area famed for its abundance of sea fireflies. Despite their impressive numbers, it still requires a little effort to get photos like the ones you see here.