Diatoms are a group of unicellular and silicified algae of considerable small size. From the functional point of view, they are individual cells that can appear as filaments, chains or colonies, either in the phytoplankton column or also, attached to the benthos. The siliceous cell wall that it contains keeps all the organs that the cell possesses and has a series of quite complex structures. The siliceous wall is transparent, and in this way allows light to enter, it is also perforated, which allows the adequate diffusion and excretion of the different waste materials. Diatoms are abundant in almost all habitats and divide in a vegetative way. So, we can say that diatoms are organisms that make up plankton.

What are diatoms?

Diatoms are a monophyletic group of algae composed of unicellular or colonial eukaryotes, almost all of them are autotrophs. They are a fundamental part of plankton and are unicellular, important for the life of the earth.

Characteristics of diatoms

The main characteristics of diatoms are as follows:

Types of diatoms

They can be classified according to the distribution of their pores. There are central diatoms that have a radial symmetry. When diatoms have a bilateral symmetry, then they are called pennades. There are four different types of diatoms: coscinodiscophyceae, mediophyceae, fragilariophyceae and bacillariophyceae.


Diatoms can perform the photosynthesis process in order to obtain organic carbon when they are in the presence of sunlight. Being an algae, it takes its food from the aquatic soil of the water, to which sunlight and oxygen are added, thus creating glucose and carbon dioxide. Some scientists say they also feed on bacteria.


Diatoms are able to live in very different habitats so they can live in freshwater and seawater and can be found around the world regardless of the local climate.

Life cycle

After they have reproduced, the growth process continues until the cells reach one-third of their maximum size. Sometime later, they die and are deposited on the bottom of the sea.


They reproduce through asexual reproduction and cell division. This means that they reproduce by bipartition by means of leaflets that increase in size forming daughter cells. These daughters continue to grow and acquire the size of an adult cell.


They are very important because they function as photosynthetic beings that fix atmospheric carbon and at the same time produce large amounts of oxygen, which is why they are fundamental in ecosystems, since they form one of the main components of the food chain. They sustain the other levels of the food pyramid. They also help to indicate the quality of water because they detect concentration of nutrients, acidity, salinity and other reactions product of the alterations caused by the human being because they even work as insecticides since it can eliminate plagues without damaging the plants or humans. They work perfectly in ant, cockroach and lice control and can also be used as fertilizer.

Diatomaceous land

Due to the great capacity of reproduction that have the diatoms, when these die, their shells are deposited in the seabed, forming what is known as land or mud diatoms. These beds, then form a series of rocks of sedimentary origin and cover the seabed and freshwater deposits. They are considered part of the land bottoms of the continents. It is mainly used as a fertilizer and natural insecticide in gardens and fields.

Examples of diatoms

Written by Gabriela Briceño V.

How to cite this article?

Briceño V., Gabriela. (2019). Diatoms. Recovered on 23 February, 2024, de Euston96:

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