aphotic

adjective2

1. •
   Having no light, especially no sunlight.
2. •
   Describing that part of deep lakes and oceans where less than one per cent of sunlight penetrates and where photosynthesis is not possible.

   • We have bacteria classified as aërobic and anaerobic, according as they thrive with or without access of air. We need to classify bacteria as photic and aphotic. — 1894