Bioluminescent Snails!

     How cool is this?  A glowing green snail!  Hinea Brasiliana.  Ok, so it's only a sea snail, not something you'll find in your backyard.  And this snippet of info disputes the green bit - but hey, a blue-white light is pretty cool as well.
     It's theorised that they use their bioluminescence as a defence mechanism, lighting up when disturbed to either try and scare away predators or simply light them up so something bigger and badder again can eat what's attacking them.
     The mechanism they use to light their shells up is pretty neat as well.  The shell actually acts like a light transmitter/splitter, picking up the light from a small bioluminescent organ and spreading it throughout the entire shell.  Sort of like one of those plastic light tubes, where a light shone on one end illuminates the whole thing.  See Fibre Flare for an example of what I mean.
     Even more intriguing, the mechanism by which the shell transmits light is wavelength sensitive - it only lights up when hit with a greeny-bluey light, it won't transmit red for example.
     Neat little thing, but not quite enough to take the coveted "favourite snail" position away from the Otways Carnivorous Black Snail, Victophanta Compacta:

     Sure, this one doesn't glow - but you have to admire the persistence of something that slow deciding it's going to live by hunting other critters.  (Unfortunately they're endangered, so it's not working out so well for them.)


Original Article: BBC