merobenthos vs benthos

merobenthos and benthos both are nouns.

Word	Noun	Adjective	Verb	Adverb
merobenthos	Yes	No	No	No
benthos	Yes	No	No	No

As nouns, benthos is a hypernym of merobenthos; that is, benthos is a word with a broader meaning than merobenthos:

merobenthos: benthos consisting of organisms in pre-adult stages that later become adult in the plankton.
benthos: organisms (plants and animals) that live at or near the bottom of a sea, lake, river or stream

merobenthos (noun)	benthos (noun)
benthos consisting of organisms in pre-adult stages that later become adult in the plankton.	organisms (plants and animals) that live at or near the bottom of a sea, lake, river or stream
	a region including the bottom of the sea and the littoral zones