First bioluminescent freshwater mollusc

- Who
- Latia neritoides
- What
- First
- Where
- New Zealand
- When
- Not applicable
The first (and currently the only) species of freshwater mollusc known to be bioluminescent is Latia neritoides, a gastropod species of freshwater limpet, found only in clear running streams and rivers on New Zealand's North Island. Its light originates from a luminescent slime that the limpet exudes when it is disturbed, or when attacked by a predator. The substance responsible for its bioluminescence is a specific type of luciferin, yielding greenish light with an emission wavelength of 535 nanometres, in a chemical reaction catalysed by the flavoprotein enzyme luciferase and a so-called "purple protein'" cofactor chemical.
Not only is this species bioluminescent, it is also biophosphorescent. That is, it absorbs short wavelengths of light and then emits them at longer, optically visible wavelengths, even after the original light source has been removed (thereby distinguishing it from a biofluorescent animal, which stops fluorescing once the light shining upon it is removed)), which means that it is seen to glow. This process is independent of the limpet's bioluminescence, involving a separate section of the colour spectrum.