As nouns the difference between microalgae and microalga
is that microalgae is plural of lang=en while microalga is any of many microscopic photosynthetic protists, often living as single cells and floating as plankton.
microalga
English
Noun
Any of many microscopic photosynthetic protists, often living as single cells and floating as plankton.
Synonyms
* phytoplankton
Antonyms
* macroalga