We explain what consumer organisms are and how they are classified. Also, some examples of these organisms.
What are consumer organisms?
Consuming organisms, also called heterotrophic organisms, are those unable to synthesize their nutrients from inorganic molecules and energy sources external, as do autotrophs (photosynthesis, for example). Therefore, consumers must feed (consume) organic matter from other living beings, to obtain energy from its digestion and decomposition.
In this way, when studying the trophic relationships of an ecosystem, one can distinguish between producer organisms (autotrophs, usually plants and / or algae) and consumer organisms, which can be of different types:
- Herbivores When they feed on the fibers and by-products of plants and other autotrophic beings.
- Carnivores. When they feed on the body of other animals, they are herbivores or carnivores. According to how they do it, we can talk about:
- Predators When they hunt other animals to consume their meat, ending their life to prolong their own.
- Parasites When they feed on the body of other animals, without killing them, although causing damage in the process.
- Scavengers. When they feed on the remains of the hunt that the predators abandon.
- Omnivores When they feed on any type of organic matter, without distinction.
- Detritivores. When they feed on decomposing organic matter, that is, corpses, manure, meat remains, fallen leaves, etc. They are nature’s recycling department.
Primary consumers
The first rung on a trophic ladder is occupied by primary consumers, also called herbivores. Are the ones they feed on the producing organisms, and are the first consumer link in the chain of transmission of matter and energy, since they serve as prey to the first level of predators, often serving as a bridge between the nutrients that plants, for example, manage to synthesize through the photosynthesis, and the rest of the meat-eating animals.
Secondary consumers
The first step of predators, that is, of carnivores, is generally composed of animals that eat animals. In many ecosystems this is the link for small carnivores, or also omnivorous animals, which feed on everything. These, in turn, serve as the transmission of nutrients and matter to a higher rung of predators, which feed on the meat of small predators, as a larger fish does from a medium-sized fish.
Tertiary consumers
Tertiary consumers are often the end of the food chain, and are known as predators, that is, consumers who they feed on primary and secondary consumers, and that they have a strictly carnivorous diet, keeping the growth of these populations at bay. In this category are the African big cats, sharks and other particularly voracious animal forms.
Quaternary consumers
Depending on the ecosystem, there may be quaternary consumers: creatures that they feed off tertiary consumers, and that occupy the final position (the top) of any form of trophic pyramid, that is, the final consumers or absolute predators. The human being is among them, since we do not have any type of natural predator (except, perhaps, ourselves).
Examples of consuming organisms
Some simple examples of consuming organisms are:
- Primary consumers. Giraffes, rabbits, squirrels, caterpillars, cows, rhinos, goats, herbivorous birds, zooplankton.
- Secondary consumers. Foxes, spiders, praying mantises, possums, seals and small hunting snakes.
- Tertiary consumers. Anaconda snakes, hawks, owls, orca whales, wild dogs.
- Quaternary consumers. Polar bears, lions, eagles, tigers, sharks, crocodiles, humans.