Green Flashing Snail – JOG ON!
Green flashes for go away! This marine intertidal known colloquially as the Yellow-Coated Clusterwink or Jockiwink snail, and formally Hinea brasiliana (Lamarck, 1822) in the family Planaxidae is found on Australia’s Eastern seaboard.
When disturbed it reacts quickly – with a series of green flashes. It can register annoyance for approximately 30 minutes at a time.
Not bad for a 21mm (0.8 inch) gastropod.
Dimitri Deheyn from the Scripps Institution of Oceanography at UC San Diego studies bioluminescence and has worked on these light emitting gastropods to discover the mechanism and delivery methods that create the pulses and glow.
Clusterwink snails defend themselves by retracting into the shell spire and omitting a pulsing light. The snail only emits a blue – green light. The flashes illuminate the whole shell amplifies the rays, akin to a dog raising it’s hackles in defence to look bigger and more fierce. Tests carried out by the Deheyn Lab found that when a white light beam was projected, most wavelengths passed through successfully (~75%) except, interestingly, for the blue-green portion. Individual colours, red, blue, etc. just didn’t work. Further tests with a carefully calibrated beam of blue – green light shone into the shell aperture showed a scattering of light throughout the calcium structure. This begs the question how is the shell structured in order to amplifies and scatter light so effectively? And, how can this be unique crystalline structure that amplifies light be applied to some gain in manufacturing, for instance?
Bioluminescence is a well documented feature of many organisms throughout the different taxa. Light emissions through the body or by way of bodily excretion are thought to distract and confuse potential predators or as a diversionary tactic signalling the position of predating attackers to even larger predators – so the primary prey may escape. The tropical land snail Dyakia striata (Family Dyakiidae) also flashes green and produces glow in the dark eggs. The earthworm Diplocardia longa is a blue flasher leaving trails of glowing blue slime. Insects – fire fly; marine crustaceans – ostracods; cephlapods, scale worms, jelly fish, bacteria, fungi, coral, phytoplankton species and other marine, freshwater and terrestrial organisms exhibit light emitting traits. The colour range is ususally between the blue and green wavelengths but red bioluminescence is also observed in some predatory deep sea barbeled dragon fish.
Next time you are out and about be sure to look for natures fairy lights – bioluminescent is everywhere!