ghostfish

/ɡoʊstˌfɪʃ/
noun
  1. A type of fish that is pale, translucent, or silvery in color, often found in deep or dark waters.
    • In the aquarium, the ghostfish looked like a shimmering shadow among the colorful tropical fish.
    • Deep-sea fishermen sometimes catch a ghostfish with eyes that glow in the dim light.
    • The ghostfish glided silently through the dark cave, its pale body almost invisible.