They don't need to see. They can sense what's around them with their lateral line. Kinda like sonar.
Well what do you do when you can't see in the dark?<br />
They trail behind the bioluminescent ones
they hide and wait for the nocturnal predators to, hopefully, not find them.
probably crap all night.
They just feel the waves
Dont fish have night vivsion? I think they do.