nanoplankton vs plankton

nanoplankton and plankton both are nouns.

Word	Noun	Adjective	Verb	Adverb
nanoplankton	Yes	No	No	No
plankton	Yes	No	No	No

As nouns, plankton is a hypernym of nanoplankton; that is, plankton is a word with a broader meaning than nanoplankton:

nanoplankton: microscopic organisms found in plankton
plankton: the aggregate of small plant and animal organisms that float or drift in great numbers in fresh or salt water

nanoplankton (noun)	plankton (noun)
microscopic organisms found in plankton	the aggregate of small plant and animal organisms that float or drift in great numbers in fresh or salt water