plankton consisting of organisms at a certain stage of their life cycles, esp larvae, the other stages not being spent as part of the plankton community
Compare holoplankton
meroplankton in American English
(ˌmɛroʊˈplæŋktən)
noun
an organism that spends only a part of its life cycle as a member of the planktoncommunity (e.g., the barnacle or starfish, in which only the larval stages are planktonic)