Today’s interesting fact has to do with the Angel Winged Clam.

The angel wing clam gained a bit of fame in the movie Sahara, where Dirk tells Dr Rojas about the clam, calling it Petricola Pholadiformis and stating that the river they were in is the only place on earth that they occur. He goes on to state that they glow in the dark, and that science has been unable to determine why. He continues that he thinks they glow, because they can.

Unfortunately the clam he identifies, doesn’t glow in the dark, is actually called the false angel wing and is found in many fresh water rivers. The angle wing clam is Cyrtopleura Costata, is found only in salt water and while some of these shells will glow if exposed to ultraviolet light, they do not produce their own light.

Some molluscs do have a bio luminance organ and produce a green light. This light can be seen glowing through the shell. In some species of molluscs this light shines brighter through the shell than others and the shells have been shown to amplify the light produced. The technique used by the molluscs for laying down material in the shells are have been determined and the method is being used by LED producers to increase the output of their devices.

As to why these creatures produce light, it seems that the brighter the light, the less predation the animals suffer in the wild. It is thought that the green light produced hides them from their predators, effectively hiding them in plain sight. It has been confirmed that at least some of these predators cannot see the frequencies produced.