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.
These are tiny plants that serve as food to many of the ocean creatures from the smallest of fish to large whales. Some scientists estimate that phytoplankton provide the earth with almost half of its oxygen! Marine plants live in the euphotic zone of the ocean because they need energy from the sun for photosynthesis. 1. Plankton-drifters, capable of only insignificant free-swimmming. More than 99% of all marine life is planktonic.