Below the mesopelagic zone it is pitch dark. This is the midnight (or bathypelagic zone), extending from 1000 m to the bottom deep water benthic zone. If the water is exceptionally deep, the pelagic zone below 4000 m is sometimes called the lower midnight (or abyssopelagic zone). Temperatures in this zone range from 1 to 4 degrees celsius and is completely aphotic.
