Bathypelagic (Midnight) Zone

 The bathypelagic zone (also known as midnight zone) is the part of the pelagic zone that extends from a depth of 1,000 to 4,000 m (3,300 to 13,100 ft) below the ocean surface. The average temperature hovers at about 4°C (39°F).

 Animals in the bathyal zone are not threatened by predators that can see them, so they do not have powerful muscles. This zone is difficult for fish to live in since it is especially hard to find nutrients. They have become very energy-efficient, and many have slow metabolic rates to conserve energy. The fish are characterized by weak muscles, soft skin, and slimy bodies.

 Because of the lack of light, some species do not have eyes. Those possessing eyes in this zone include the viperfish and the frill shark. Many forms of nekton live in the bathyal zone, such as squid, large whales, and octopuses.

Synopsis:

• Animals are energy-efficient and have slow metabolic rates.
• The depth extends from the 1,000 to 4,000 meters (3,300 to 13,100 ft).
• Sunlight does not reach this zone, meaning photosynthesis is impossible.
• The average temperature hovers at about 4°C (39°F).