Plankton are not a specific time of fish at all. It is a term for any drifting organism that inhibits a certain zone in a body of water. They are defined by their ecological role.
Plankton are small organisms which live in ocean some of which are only 1/1000 of a millimetre with the largest types over 1 meter. whales feed on them.
Different species of Plankton can be considered fish or non fish. Some single cell bacteria are considered plankton but not fish. Plankton may also be multicultural organisms such as jellyfish.
