2 All of the major phyla of animals are represented in the plankton All of the major phyla of animals are represented in the plankton. Remember: In the sea, microscopic plantlike organisms form the base of the food chain.
3 This means most of the organisms that feed on these plant like organisms are also small.
4 With such a wealth of microscopic food, organisms take advantage of this rich food supply either as a larval form or as an adult.
5 Some of these organisms are herbivores feeding on the microscopic plants. Some are predaceous carnivores which feed on the herbivores or other carnivores.
6 Those organisms that spend their entire life as plankton are called holoplankton.
7 Those organisms that spend part of their life as plankton are called meroplankton.
8 We'll take a look ata few examplesfrom each group!