Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
The aphotic zone refers to the deeper layer of a body of water that receives little to no sunlight. It is characterized by darkness and low levels of dissolved oxygen.
The photic zone is the upper layer of a body of water where sunlight can penetrate and support photosynthesis. It contrasts with the aphotic zone as it receives ample sunlight.
Deep-sea Creatures: These are organisms adapted to live in extreme conditions found within or near the aphotic zone of the ocean. They have unique adaptations to survive in darkness and high pressure.
Chemosynthesis: In the aphotic zone, where sunlight is absent, certain bacteria and other organisms can use chemicals from hydrothermal vents or other sources to produce energy through chemosynthesis.