colloid. 1  a solid, liquid, or gaseous substance made up of very small, insoluble particles (as single large molecules or masses of smaller molecules) that remain in suspension in a surrounding solid, liquid, or gaseous medium of different matter.
Nekton. Nekton are the animals that can move by themselves in the ocean waters. Nekton live in all zones of the ocean. However, just like benthos and plankton, most live in the sunlight zone or shallow twilight zone since there is the most sunlight and it is easy to feed on smaller organisms such as krill and minnows.
Most plankton is microscopic, especially that found in freshwater. Marine plankton have exclusively whole groups of organisms that are very visible to the naked eye, e.g. Ctenophores (sea gooseberries). All plankton is divided into the plant-type plankton, the phytoplankton, and the animal plankton, zooplankton.The latter can be further sub-divided into the temporary and permanent zooplankton. The temporary tends to be those which are larval forms of adults living on the seashore, e.g. barnacle larvae called nauplii.tenophores (sea gooseberries). All plankton is divided into the plant-type plankton, the phytoplankton, and the animal plankton, zooplankton. The latter can be further sub-divided into the temporary and permanent zooplankton.