WHAT IS DETRITUS? (IN BIOLOGY, GEOLOGY AND MEDICINE) - SCIENCE - 2025

Detritus is a Latin word that means worn and is used to define the result obtained from the disintegration of a solid mass into particles. The term is widely used in biology to define decomposing biogenic remains, however, in other sciences it is not necessarily used with the same meaning.

Sometimes the form detritus (singular) or detritus (plural) is used, and it can also be used as an adjective, that is, detritic. Despite being widely used in biology, there are discrepancies as to the inclusion or not of decomposing microorganisms within what is defined, in this science, as detritus.

Turtle grass (Thalassia testudinum) in the foreground with mangrove detritus and mangrove leaves and roots (Rhizophora sp.) In the background. Photograph by the NOAA CCMA Biogeography Team. Taken and edited from

In biology

Scientist R. Darnell defined detritus as any type of biogenic material (organic matter) that has undergone different levels of decomposition by microbes and that can be used as an energy source by consuming organisms.

Detritus is basically made up of dead organisms, or part of them, such as leaves, trunks, roots (plant remains, slower decomposition), bones, shells, scales (animal remains), among others. The fecal remains of the animals are also included; different species of microorganisms decompose these remains.

As the remains of organisms decompose, smaller remains are obtained. Additionally, humic substances (or humus) are formed, which are resistant to new decompositions.

Importance of detritus

Not all the biomass produced by autotrophic or heterotrophic organisms is used by organisms of the higher trophic level, on the contrary, the vast majority of biomass, at least the plant biomass, is finally deposited in the soils when the organisms die.

This biomass is decomposed to form detritus, which will be used as an energy source by detritivore organisms and will sustain what is known as detritus food chains.

For example, in mangrove ecosystems, one of the most productive in the world, the detritus food chains supported by decaying litter can be quite complex and diverse.

Detritus and its use by detritivores affects trophic structures as well as community dynamics, since it allows to support a greater diversity of species in an ecosystem, mainly predatory organisms, on which it could exist if it were solely and directly dependent on the producers. primary.

Additionally, detritus helps stabilize the energy flow of an ecosystem. It can even alter the configuration of the community structure by inhibiting the presence of some species and favoring the presence of others.

Classification of detritivores

Organisms that feed directly on detritus are called detritivores or saprophagi. Within these are found from protists to vertebrates, and can be classified according to their feeding mechanisms into two types; selective and non-selective.

Selective detritivores

Organisms that feed on the organic matter present in the sediment, therefore, make a prior selection of the material they are going to eat. For example, fiddler crabs (Uca, Minuca, and related genera) are selective detritivores.

These crabs take portions of sediment and carefully separate the organic matter (detritus) of the sand grains from it, using specialized structures to do so. Once both materials are separated, they will only eat the detritus.

The grains of sand, cleaned of organic matter, are accumulated in the form of small sand balls that they deposit on the ground, without having ingested them.

Non-selective detritivores

They are organisms that ingest sediment to take advantage of organic matter during the feeding process. For example, sea cucumbers and sand dollars are non-selective detritivores.

In geology

For geology, detritus is the disintegrated material or sediment of rocks, produced by different processes that include diagenesis, weathering and erosion. Diagenesis is the set of physical and chemical reactions that occur between minerals, or between minerals and fluids in the sedimentary process.

Weathering is the set of processes that cause the destruction of rocks by atmospheric agents. On the other hand, erosion includes weathering and the transport of disintegrated material to sedimentary deposits.

The detritus will be deposited in the sedimentary basins, there they can be compacted giving rise to the so-called sedimentary rocks. On the other hand, the waste thrown by volcanoes is also called volcanic detritus.

A detritus cone, on the other hand, is the accumulation in a valley, of pieces of rocks, stones, etc., that acquire this geometric shape when detached from the slopes or cliffs of a mountain.

An example of sedimentary deposits are sandy beaches. According to the geological definition, sands are detritus formed by remains of solid materials decomposed into very fine fractions. These fractions are mainly fragments of siliceous rocks, also remains of mollusk shells, corals, among others.

Another common example of detrital materials is clays. These are formed from aluminum, sodium, potassium or calcium silicates (feldspars). For the formation of clays, the disintegration of the feldspars by atmospheric agents must occur.

Detrital sedimentary rock. Taken and edited by Beatrice Murch from Buenos Aires, Argentina.

In medicine

Detritus in medicine is material from the disintegration into particles of solid materials and cellular debris products, and dead cells. It is particularly taken into consideration in dentistry and traumatology.

odontology

In endodontics, detritus is the material composed of dentin chips, as well as living or dead residual tissue that adheres to the walls of the root canal of the teeth. This detritus forms what is known as smear layer.

Endodontic treatments cause debris due to wear and tear caused by surgical instruments on the teeth. This detritus is difficult to eradicate due to the configuration of the root canals, which tend to occlude, and because its removal causes more dentin remains that can create new detritus.

Traumatology

The implantation of bone prostheses to repair damage caused by trauma or wear causes the formation of debris during the drilling of the bones. Wear over time of prosthetic material, such as bone cement, also produces debris.

The detritus and necrotic tissue caused by drilling create the conditions for the growth of microorganisms and abscesses that can complicate and put the success of the transplant at risk.

Additionally, detritus caused by mechanical friction and wear on the bone cement are a potential cause of osteonecrosis and osteolysis in patients with implants.

References

1. EP Odum (1978). Ecology: The link between the natural and social sciences. Editorial Continental, SA
2. JC Moore, EL Berlow, DC Coleman, PC de Ruiter, Q. Dong, A. Hastings, NC Johnson, KS McCann, K. Melville, PJ Morin, K. Nadelhoffer, AD Rosemond, DM Post, JL Sabo, KM Scow, MJ Vanni & DH Wall (2004) Detritus, trophic dynamics and biodiversity. Ecology Letters.
3. P. Mason & L. Varnell (1996). Detritus: Mother Nature's Rice Cake. Wetlands Program Technical Reports.
4. Detrirus. On Wikipedia. Recovered from en.wikipedia.org.
5. Sedimentary rocks. In Virtual Museum. Recovered from gob.mx.
6. G. Ramos, N. Calvo, R. Fierro (2015). Conventional adhesion in dentin, difficulties and advances in the technique. Journal of the Faculty of Dentistry, Universidad de Antioquia.