Photographers Trevor Williams and Jonathan Galione of Tdub Photo were strolling Okayama when they came across an eerie yet captivating blue light off the coast. Enthralled by its beauty, the photographers decided to capture the rare sight.

Apparently, the blue light is emitted by the bio-luminescent shrimp called Vargula Hilgendorfii. Locally known as "umihotaru," the Vargula Hilgendorfi is just one of three bioluminescent species of ostracod crustacean in Japan. "Umi" means sea and "hotaru" means firefly.

They are often referred to as "sea fireflies" because of the light that they emit. According to a study published in National Center for Biotechnology Information, the luminous secretion of the marine crustacean is due to a simple enzyme-catalyzed reaction involving only luciferase, luciferin (substrate) and molecular oxygen.

There is not much documented profile about the species but Animals Life Resource notes they usually measure 3 millimeters in length and have a beak-like projection on the front of the smooth, round, clear carapace.

They exist in shallow waters with sandy bottoms along the Pacific coast of central Japan. They feed on dead fish and worms.

Williams and Galione showcased the beauty of the tiny creatures in a photo series called, The Weeping Stones.

In an interview with Lonely Planet, they narrated how they were able to capture the critters in groups.

"We bought several big glass jars from a hardware store, the kind Japanese people often use for making sake at home. We drilled a few holes in the lid before covering them with heavy duty tape and rope. Next, we added bait in the form of raw bacon, putting a few pieces into each jar and securing the lids before setting them into the water," Gallione explained.

"It's important to spread the jars out and not to just drop them all in one area. That way you can maximise your catch. This is where the rope comes in handy. By running the top back to the beach and tying it a rock or stick, you can ensure that you don't lose track of your jars and prevent them from getting washed out with the tide," William added.

After a few hours, they were able to catch the glowing shrimps. To add artistry to their photos, they spread the glowing shrimps on boulders until they swam freely on the body of water, creating fluidity and movement.