Data collected by the Interdisciplinary Centre for Marine and Environmental Research at the University of Porto (CIIMAR-UP) showed the research centre's contribution to taxonomy. Since its creation 25 years ago, CIIMAR researchers have been involved in the discovery of 117 new aquatic taxa, 90 of which are new species to the world scientific community.

In the course of the sixth largest mass extinction of species on planet Earth, it has never been more important to know the biodiversity that inhabits it. The majority of our planet's biodiversity exists in the oceans, which are also home to most of the species we don't yet know about, biodiversity commonly known as the ‘dark taxa’. Taxa are the taxonomic unit associated with the scientific classification of living beings into kingdom, phylum, class, order, family, genus and species, and which allows us to organise species among themselves.

CIIMAR researchers have always been involved in describing new marine and aquatic taxa or have collaborated on articles describing them. These researchers have contributed to the description of 101 aquatic taxa that inhabit both estuarine and marine environments in various geographical areas. This biodiversity of more than a hundred organisms new to science ranges from large taxonomic ranks, such as 1 new order or 2 new families, to more specific taxonomic ranks that include 22 genera, 90 species and 1 variety new to science.


The importance of taxonomy

Taxonomy plays a fundamental role in making the biodiversity it describes available to society. Only once a species has been described will society have new units of life that it can use as a biological resource, whether in the field of medicine, cosmetics, architecture or many others. At this point, biodiversity also gains from having a name because it can then be included on lists of threatened species and in nature conservation plans.

Bacteria, sponges and cnidarians top the list

The biodiversity described by CIIMAR researchers includes mostly marine species. In this biodiversity, most of the taxa described were bacteria (30), followed in number by sponges (24), and then by cnidarians that endoparasise fish, the Myxozoa (20). The rest include organisms such as cyanobacteria, water bears or tardigrades, fish, microalgae, diatoms, platyhelminths, copepods and nematodes.

Most of the bacteria described by CIIMAR researchers belong to the Phylum Planctomycetota and often occur in biofilms associated with macroalgae or sponges. For example, a sample of sea lettuce (Ulva sp.) collected in Viana do Castelo led to the discovery of a biofilm with the new genus Roseimaritima, named after the pink colour of the bacteria.

As far as sponges are concerned, the most recent sponge species to be described by CIIMAR researchers, Hemimycale funchalensis, is from the island of Madeira. Its name, although not related to its place of distribution, honours the Natural History Museum, located in the city of Funchal, for its work in preserving Madeira's marine fauna.

As for Cnidarians, the work of CIIMAR researchers has resulted in the discovery of 20 new species of obligate endoparasites of bony and cartilaginous fish. As an example, the species Chloromyxum dasyatidis was recently discovered in Tunisia and found in the gall bladder of the common skate Dasyatis pastinaca.

Among new taxa, 20 species of cyanobacteria have also been described at CIIMAR. CIIMAR's reference collection of cyanobacteria, LEGE-CC, preserves more than 2,000 strains that are used for scientific research in the field of blue biotechnology and the description of new biodiversity. In 2024, on the occasion of CIIMAR's anniversary, the new genus Ciimarium was described in its honour, which includes the new species Ciimarium marinum, isolated from the vicinity of the port of Leixões.

A legacy with an impact on the future of science

The total of 117 taxa described in 25 years of existence is a legacy that CIIMAR leaves for posterity. This legacy is being publicised today, the day of the final event of the Portuguese Blue Biobank, a national network of biobanks that CIIMAR coordinates and to which it contributes with the creation of new reference biological collections. These collections enhance the discovery of new diversity and the work of current and future taxonomists, who can use them as a comparative base and repository for the marine specimens and strains described.

Undescribed marine biodiversity or ‘dark taxa’ is more numerous than we already know. Many marine species await our attention. In this sense, taxonomy is fundamental to knowing, enjoying and conserving marine biodiversity. In the future, we hope to see the essential work of taxonomy bring more biodiversity to CIIMAR's attention.

Ends. Media enquiries to Eunice Sousa, esousa@ciimar.up.pt.