Smart creatures seen in Thailand emit rare ‘continuous green light’. See them shine

Bioluminescence, the effusion of light from living things, is extremely common in the marine world. In fact, the majority of aquatic species, 76%, have the ability to glow in the dark, according to one study.

In contrast, few terrestrial animals have this power of self-illumination. It can be seen in glow worms and fireflies, just a few other natives.

Of the thousands of species of land-dwelling mollusks – including snails and slugs – only one was known to glow in the dark.

That is, until now. Researchers recently discovered four types of snails that can set themselves on fire, according to a study published on September 13 in the journal Scientific Reports. The slimy creatures were found to emit a “continuous green light”.

Researchers made this discovery after scouring Thailand for snail specimens to conduct tests over a period of several years.

The slow-moving creatures were hand-collected during “intensive” explorations throughout the country’s rainy season.

Once caught, they were placed in plastic containers, given vegetables and mushrooms to snack on, and taken to a laboratory for analysis.

After their genomes were sequenced, the specimens were identified as belonging to four species in the Phuphania genus: P. crossei, P. globosa, P. carinata and P. costata.

Then the snails were taken for a photo shoot in a dark room, so that their bioluminescence, if it existed, could be captured on camera.

Tissue samples were also taken and analyzed under microscopes for light-emitting cells.

Through these processes, researchers discovered that the four species could indeed transform themselves into living glow sticks and did so without prompting.

They appeared to emit a steady green light, which could be turned on and off at will, for long periods of time.

“The controlling factors and the mechanisms are unknown,” researchers said, adding that “the Phuphania snails appeared to retain their bioluminescent abilities for several weeks after collection, even in hibernation.”

The snails’ bioluminescence probably allows them to ward off predators, researchers said.

The internal lighting may help the creatures mimic other bioluminescent organisms, such as fireflies and certain mushrooms, which are associated with bad taste or toxicity.

“It is suggestive that the luminescence color of Phuphania is green, like firefly eggs and pupae and mushrooms; green is probably the most visible color for nocturnal predators in terrestrial settings,” said researchers.