The answer is Bathypelagic zone.
This zone is also called as midnight zone, being a part of pelagic zone it extends upto 1,000 to 4,000 meter below the surface of ocean. It lies between the mesopelagic and abyssopelagic zone. Sunlight does not reaches this zone. There are no plants in this zone because it lacks sunlight and hence no photosynthesis takes place there. Some fishes in this region have no eyes.