hypobenthos

Century Dictionary and Cyclopedia

1. n. The animals that live upon or in the bottom of the deep sea, below the 500-fathom line, considered collectively: contrasted with the epibenthos, or fauna and flora of the bottom in shallow water, and the mesobenthos, or the inhabitants of the bottom between 100 and 500 fathoms; the abyssal benthos. One of the most remarkable results of the exploration of the deep sea is the discovery that the bottom, even under more than five miles of water, supports a rich fauna of characteristic animals, living under conditions which had long been supposed to be incompatible with life. Their bodies support a pressure which, in the greatest depths, is more than five tons to the square inch, and they live in water that is always near the freezing-point, in total darkness except for the light which they themselves produce by means of luminous organs. Since plants are completely absent in the depths, the only ultimate source of the food of these animals is the rain of dead plants and animals which is constantly falling upon them from the higher levels. See benthos, epibenthos, mesobenthos.