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.
The pelagic zone refers to the open ocean, away from the shore. Depending on depth, the pelagic zone varies widely in amount of sunlight, temperature, and pressure. This ocean habitat is home to a vast array of marine organisms including plankton, large and small migratory fish, marine mammals and reptiles.