Definitions for "nekton"
Keywords:  plankton, pelagic, squid, swim, aquatic
The aggregate of actively swimming animals in a body of water ranging from microscopic organisms to whales.
swimming organisms that are able to move independently of water currents (opp. plankton). These include most fish, mammals, turtles, sea snakes, and aquatic birds.
Collective term for free-swimming organisms in aquatic ecosystems, as opposed to plankton.
in an Illinois lake would include bluegill, crappie and bass.
Nekton is the grouping of living organisms that live in the water column of the ocean and freshwater lakes.
Taken from Encyclopaedia Britannica 2002