The aphotic zone is a layer of the ocean where sunlight does not penetrate, typically found at depths greater than 200 meters (656 feet). In this dark environment, photosynthesis cannot occur, making it challenging for most life forms to survive. Organisms in this zone rely on other sources of energy, such as organic matter that sinks from the upper layers. This zone is home to unique species adapted to extreme conditions, including high pressure and low temperatures. Creatures like deep-sea fish, squid, and bioluminescent organisms thrive here, showcasing fascinating adaptations to life in complete darkness.