In the deep, darkness is the blanket that swaddles us all. But within this blanket, interlopers abound like bedbugs. Tiny pinpricks of light, softly glowing in a multitude of shades, make their way amidst the black.
Light attracts life. Everyone knows this. Even the creatures with teeth and death on their minds. The light is safe and never-safe. Watch your back.
The largest of the common luminescent are the sunfish. Large, flat, almost circular except for their fins - the sunfish do resemble their namesake. Their light is soft though, like the reflection of the moon in a lake. They move slowly, drifting through kelp forest and rocky reef with a calmness and inner peace that is hard to imagine in the desperate darkness of the deeps. Predators don’t often attack them - they are too useful. Instead, they hang back, waiting in the darkness just outside the reach of their glow. Like watering holes in a savannah, seeing a sunfish is a relief and a warning. You are probably not alone.
The moonfish are smaller, rarer creatures. And they do not always emit light. Deep sages have found so-called dark moon fish that are the same as their luminous cousins but like a torch that has not been light, they sit inert. Obari wisdom says that like the secrets of the lovers’ heart, just because you cannot see some moonfish light, does not mean that it isn’t there. Obari salvagers often carry cages of dark moofish when they go seeking. Seeing a moonfish is often considered to be good luck and they are the only creatures that can make even a stargazers stop talking and just observe.
Landsiders don’t think of starfish as luminescent because often they are not. But fed a certain algae that the Obari grow, starfish begin to glow. A small, pulsing light that emanates in waves, throbbing against the darkness before fading away. Starfish are natural lanterns because their brightness can be moderated by how much algae they are fed. They are easily the cheapest form of modular light that can be used by intrepidaires.
There are many other sources of light, of course. Some used by predators - deranged, monstrous anglerfish that dangle a drop of light to lure prey or glimmerworms marching across the seafloor. The earlier allegory holds true - light in the deepside is like water when you’re landside: potentially dangerous but essential. Working in the darkness means you only see the gaping jaws just before they snap shut.