Swimmingly peacefully through the dark waters of the ocean the world over are marine planktonic polychaete worms in genus Tomopteris These mesmerizing creatures are relatively transparent until they shine a deep bioluminescent blue. One species, Tomopteris nisseni, is one of the few creatures on the planet to produce yellow bioluminescence.
Europa: Sea Life A squid-like creature feeds on the bottom of the salty ocean thought to exist below the icy crust of this moon of Jupiter. Europa is the only large body, other than Earth, that may have large volumes of water capable of supporting life. If organisms exist in this perpetually dark sea, they may exhibit characteristics of deep sea creatures in Earth's oceans, including bioluminescence and a nutrient chain based around hydrothermal vents.