These tiny copepods don’t even look like animals. Most of the time, they look like blue flashes of light in sea water. The millimeter-long creatures have the ability to give out bursts of light and then turn completely transparent.
It belongs to the genus Sapphirina, and its skin – which can flicker from brilliant blue to near-invisible in an instant – is something you truly need to see to believe.
Beautiful. You see them glow blue one second and then they turn invisible the next. You're never sure if these Sapphirina copepods are real until you see them light up like a stunning firefly but for the ocean. And then they disappear just quick enough to make you question what you just saw.