benthon

noun

1. The habitat at the bottom of a body of water.

   “The simple trophic relations in the plankton do not demand such a wide variety of adaptations as do the complex relations in the benthon where, in addition to microphagous herbivores, there are also macrophagous ones and an^([sic]) unique of detritus feeders which build up animal protoplasm on the sea floor.”