AbyssIlluminating was found by rho (#406) in the Dark Forest at 2020-10-30 04:45:50.
As long wavelengths of light (i.e. red) do not reach the deep sea from the surface, many deep-sea organisms are insensitive to red wavelengths, and so to these creatures red-colored objects appear black. The red photophore of Malacosteus thus allows it to illuminate prey without being detected.
- Wikipedia, Stoplight Loosejaw