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.
There are three main types of plankton: 1  Plant plankton, also known as phytoplankton â single-celled photosynthetic organisms which manufacture food using energy from sunlight. 2  Zooplankton â single-and many-celled animals that feed on live plankton. Plant plankton, also known as phytoplankton â single-celled photosynthetic organisms which manufacture food using energy from sunlight. 2  Zooplankton â single-and many-celled animals that feed on live plankton.