Consumers - Biotic Components
These are also called as phagotrophs or heterotrophs. The organisms grouped under this category cannot manufacture their own food but obtain their energy and nutrients by feeding on other organisms. Some eat primary producers (green plants) to get their food supply and are called herbivores. In terrestrial ecosystem typical herbivores are insects, birds and mammals. Two important groups of herbivores mammals are rodents and ungulates. Primary consumers also include parasites (fungi, plants or animals) of plants. In aquatic ecosystems (freshwater and marine) the typical examples of herbivores are: small crustaceans and molluscs. Most of these organisms such as water fleas copepods crab larvae, mussels and clams are filter feeders and extract the minute, primary producers from water.