The bright blue stripes that color the rocks just off the coast of Okayama beach, Japan, are not strange special effects, but very small luminescent living beings, called “sea fireflies” or, in Japanese, umi-hotaru. Scattered in the sands of shallow ocean water, these 3mm long tiny bioluminescent shrimp look like tiny blue gems washed up on shore.
These small are able to emit a powerful light beam that can make the beaches and the Japanese sea a true multicolored spectacle: grouped together their natural light can be breathtaking.
In 2015, photographers Trevor Williams and Jonathan Galione made this series called “The Wepping Stones”, first lured groups of sea fireflies into jars with raw bacon and poured them over nearby rocks. The animals have not suffered consequences, returning quietly in their marine habitat, but leaving behind a splendid light blue trail, testimony of their path over the rocks of the beach.
The scientific name of the firefly is Vargula hilgendorfii, and is one of the three bioluminescent species known in Japan as umi-Hotaru (海 蛍). The scientific classification names them as “ostracod crustaceans”, and is the only member of the genus Vargula to inhabit the waters of Japan. The other members of its kind live in the Gulf of Mexico, in the Caribbean Sea and along the coasts of California. Lastly the number of umi-Hotaru has dramatically fallen due to human influence. During the Second World War the Japanese soldiers also used them to make themselves light at night.