Detritivore — Definition, Role & Examples
What is a detritivore?
Detritivores are heterotrophic animals that feed on dead, particulate, organic material (chiefly plant matter). Detritivores are important parts of land and marine ecosystems and are found throughout all trophic levels. Synonyms are detrivores, detritophages, detritus feeders, or saprotrophs.
What do detritivores eat?
Detritivores are detritus feeders. Detritus is particulate, decaying matter such as decaying leaves, bark, roots, stems, animal feces, and the bodies of dead animals.
When organisms die, they break down into their chemical components. Decomposition includes particulate matter (solids like crumbs and bits) and dissolved matter (liquids).
Why are detritivores important?
Detritivores are beneficial to the environment because they clean up decaying matter. Without detritivores, the earth would be buried in detritus. The major role of detritivores in ecosystems is cycling nutrients essential to the carbon cycle, phosphorus cycle, and nitrogen cycle.
Examples of detritus are orange peels, eggshells, and dead leaves. This organic matter is eaten by detritivores and is excreted out as soil. The soil is full of nitrogen and other elements necessary for trees and plants to grow.
Humans use, eat, wear, and drink organic matter all the time, hardly thinking about the decaying matter we leave behind. It goes into the garbage or, better, into compost heaps.
Humans could not exist without the work of detritivores. The important role of detritivore animals is to eat decaying plant and animal matter, feed on feces, pig out on dead plants, and lunch on decaying leaves. Detritivores are a vital part of the food chain.
Detritivore vs. decomposer
All detritivores are decomposers, but not all decomposers are detritivores. Decomposers are a category of organisms, including detritivores, fungi, and microorganisms like bacteria and protists. Fungi and bacteria are not heterotrophs; they make their own food. They extract nutrients on a molecular level using biochemical reactions.
Detritivore examples
You can find examples of detritivores, such as earthworms, termites, crabs, and flies, in just about every ecosystem. Every ecosystem must include decomposers to process dead organic matter.
Forests, backyards, and woodlands of North America have several detritivores:
Earthworms
Woodlice
Springtails (wingless arthropods)
Millipedes
Slugs
Dung flies
These detritivores eat dead organisms, dead wood, and other dead material. They work alongside decomposers like mushrooms, toadstools, and bacteria.
The giant millipede, which can reach nine inches in length, is a notable detritivore of tropical rainforests worldwide. Others include:
Dung beetles
Termites
Leaf-cutter ants
Velvet worm
Leaf beetles
Partula snail
Earthworms
These work alongside major scavengers such as army ants and the King Vulture to recycle the rainforest’s abundant growth.
Water ecosystems all have a benthic zone, the bottom of a lake, pond, sea, or ocean where waterborne organic matter falls and is broken down by detritivores and decomposers. Marine detritivores include:
Crabs
Lobsters
Sea cucumbers
Sea stars
Urchins
Marine worms such as the Christmas tree worm and bristle worms
Crustaceans such as crab and lobsters are often referred to as bottom feeders.
Perhaps the last place you would expect to find animals dining on animal feces, dead bodies, and plant litter would be the arctic or Antarctic regions. Antarctica is home to detritivorous worms and snails.
These work with bacteria and fungi, even in the severe dry and cold environment, to return nutrients to the frigid ecosystem.
The Arctic is home to carrion beetles, nematodes, and flies that all are detritivores and hasten decay in plants and animals. The other decomposers – fungi, bacteria, slime molds, and lichens – take a larger than usual role in this harsh environment.
Frequently asked questions
Let’s see how well you digested the information about detritivores. Answer these questions, and then check your work against the answers below.
Which of the following is a detritivore?
Coyote
Sea cucumber
Bacterium
Which term describes a detritivore?
An organism that eats dissolved organic waste for nutrients
An animal that eats particulate dead matter such as decaying animal parts, leaf litter, and feces
A bacteria or fungus that uses biochemical reactions to absorb nutrients from plant matter
Which of the following is a role of a detritivore?
Apex predator
Predator
Carnivore
Omnivore
Decomposer
Here are the answers:
A sea cucumber is a detritivore.
An animal that eats particulate dead matter such as leaf litter, animal remains, and feces describes a detrivore.
A decomposer is a role of a detritivore.