This fascinating video captures a glimpse of the weird and wonderful animals that live in the aphotic zone. The aphotic zone (aphotic from Greek prefix á¼- + Ïá¿¶Ï "without light") is the portion of a lake or ocean where there is little or no sunlight. It is formally defined as the depths beyond which less than 1% of sunlight penetrates. Consequently, bioluminescence is essentially the only light found in this zone. Most food comes from dead organisms sinking to the bottom of the lake or ocean from overlying waters.