bentho-, benth-

(Greek: deep, depth; the fauna and flora of the bottom of the sea; sea bottom; depth [by extension, this element includes lake, river, and stream bottoms])

macrobenthic (adjective) (not comparable)
Relating to a somewhat large organism that exists on or in the bottom of a body of water: A few macrobenthic creatures include polychaete worms, sponges, and crustaceans.
macrobenthos (s) (noun) (no pl)
A larger organism of the benthos, exceeding one mm in length: While Jill was gazing into the stream, she could really see a macrobenthos in the depth of the water!
meiobenthic (adjective) (not comparable)
Pertaining to meiofauna, which are small benthic invertebrates: Such meiobenthic organisms live in the sedimentary environments with fresh water and marine conditions.
meiobenthos (s) (noun) (no pl)
That section of the benthos that includes animals neither small enough to be grouped with the microfauna nor large enough to be grouped with the macrofauna: Small benthic organisms, termed the meiobenthos, can pass through 1 mm mesh sieve, but are retained by a 0.1 mm mesh.
mesobenthic (adjective) (not comparable)
Concerning living things dwelling in or on the bottom of the deep ocean: Mesobenthic animals and plants thrive in the depths of seas between 100 and 500 fathoms.
mesobenthos (s) (noun) (no pl)
Organisms inhabiting the seabed in the archibenthal zone, between 200 and 1,000 meters in depth: Mesobenthos include flora and fauna that live at the sea bottom at depths of 100-500 fathoms (180-900 meters).
microbenthic (adjective) (not comparable)
Relating to the benthic creatures that are not longer than 1 mm: In his biology seminar, Gerald learned about the minute microbenthic organisms that live in the depth of great oceans and seas.
microbenthos (s) (noun) (no pl)
Microscopic benthic organisms less than 0.1 mm in length: The tiny, infinitesimal microbenthos was hardly visible through the microscope.
nectobenthic (adjective) (not comparable)
A tiny creature than swims freely near the deepest part of an ocean: Tom saw photos of nectobenthic organisms in his biology book and learned that they could whirl around and move quite easily without restraint.
nectobenthos (s) (noun) (no pl)
An organism that swims actively just above the bottom of the sea, a lake, or another body of water: Jack was able to see the small nectobenthos swirling around at the lowest part of the stream close to his home.
nektobenthic (adjective) (not comparable)
Descriptive of an organism that moves near the bottom of a sea: Susan saw a film on TV about nektobenthic creatures swimming around at the lowest points of a lake, which was excellent information for her biology class at school.
nektobenthos (s) (noun) (no pl)
The form of marine life that exists just above the ocean bottom and occasionally rests on it: The nektobenthos is typically associated with the benthos that swim actively in the water column at certain periods.
phytobenthos (s) (noun) (no pl)
The aquatic flora of the region at or near the bottom of the sea: Plants or algae that flourish at the lowest areas of a lake or ocean are termed phytobenthos.
pseudobenthonic (adjective) (not comparable)
Concerning such pelagic creatures that thrive on solid material: Jenny wrote about pseudobenthonic organisms that exist while being attached to drifting or floating vegetation or other living things.
pseudobenthos (s) (noun) (no pl)
The assemblage of pelagic organisms that live attached to solid bodies: Pseudobenthos, or pseudoplankton, fixates itself to floating plants, organisms, or debris in streams, rivers, or in the sea.

Inter-related cross references, directly or indirectly, involving the "sea" and the "ocean" bodies of water: abysso- (bottomless); Atlantic; batho-, bathy- (depth); halio-, halo- (salt or "the sea"); mare, mari- (sea); necto-, nekto- (swimming); oceano-; pelago- (sea, ocean); plankto- (drifting); thalasso- (sea, ocean).