Plazi Mission

Plazi is a non-profit organisation founded in 2008 to promote the free accessibility of scientific data, in particular taxonomic treatments and images.

What are taxonomic treatments?

A taxonomic treatment is the scientific description of a biological species, i.e. an animal species, a plant species, a fungus or a bacterium. If, for example, an unknown animal species is discovered today, a single individual of this species is selected, the so-called holotype. The species is then given a name that has not been used before and formed according to predefined rules, it is described scientifically and the description is published. The holotype is the ultimate reference specimen.

The description contains a list of the external characteristics of the individuals of the species, the time and place of the discovery, the etymological derivation of the name and information on which natural history collections they are deposited in. Some descriptions include DNA analyses, information on the distribution of the species or on how the species can be distinguished from similar species, etc. Often such descriptions also include illustrations showing the individual as a whole or specific details. However, a treatment can also be an addition to an already known species description, for example if the distribution of a species has changed or if it turns out that a supposedly new species is identical to an already known species.

We do not know what we already know

But how can we be sure that a probably new species that has been discovered has really never been described before? By searching the already published treatments for a suitable description and comparing already existing illustrations. Unfortunately, there is neither a complete list of known species nor a searchable database of all published treatments. The majority of treatments are contained in an estimated 500 million pages of books stored in scientific libraries, some of which have been out of print for decades and cannot be accessed digitally. This makes searching enormously time-consuming, inefficient and also simply unfeasible in practice.

This is where Plazi comes in, by indicating treatments in scientific articles and books and making them FAIR. FAIR stands for Findable, Accessible, Interoperable and Reuseable. The data are stored in our own databases, in particular in Plazi’s own TreatmentBank and in the Biodiversity Literature Repository, and linked to each other so that they can be found, analysed and reused using search engines. The long term preservation of the liberated data is secured through the collaboration with the Zenodo repository at CERN which is hosting the Biodiversity Literature Repository.

We take treatments of animals, plants, fungi and bacteria from existing literature on the one hand, and from daily research publications on the other, and integrate them into our TreatmentBank. The data in the TreatmentBank can be freely accessed anywhere and is fed into the Global Biodiversity Information Facility database, for example.

Our motivation

In order to slow down and, if possible, stop the global extinction of species, knowledge about individual species is eminently important. Only what is known can be specifically protected. By making as much information as possible accessible and available efficiently and free of charge, we contribute to the scientific study of our environment as well as to raising humanity’s awareness of the diversity of nature and the need to preserve and protect it. We are also helping to narrow the knowledge gap between North and South and to ensure that data is also available in the tropics, where the greatest biodiversity exists.

Since its foundation, Plazi has opened up access to well over 800,000 treatments and 450,000 illustrations from almost 78,000 articles and books. As a result, Plazi already has the largest digital and freely accessible collection of scientific treatments. It is estimated that there are around 8.7 million species worldwide,1 although the numbers vary considerably depending on the different studies. So far, 2.13 million species have been described scientifically, but this also includes a number of species that have been described several times due to the lack of accessibility of the data. So there is still a lot to do, but our TreatmentBank is growing daily. In 2022, 47,373 treatments from 4,359 papers and about 30,000 images were made available, including 7,385 treatments of species that were only discovered and described as new in 2022!


  1. Mora, Camilo, Derek P. Tittensor, Sina Adl, Alastair G. B. Simpson, und Boris Worm. “How Many Species Are There on Earth and in the Ocean?” PLOS Biology 9, Nr. 8 (23. August 2011): e1001127. https://doi.org/10.1371/journal.pbio.1001127↩︎