Speaking to the Lusa agency, André Gomes-dos-Santos, a researcher at the center of the University of Porto, explained that the sequencing of the river mussel genome, published in the DNA Research magazine, by Oxford University Press, is “a first step” for the knowledge of the species.

The river mussel, whose scientific name is 'Margaritifera margaritifera', is known for its pearls, and generally only one in 3,000 contains these precious stones that became popular around 600 BC (BC) and whose use is evidenced in jewellery from royal families in the United Kingdom, Sweden, Austria and Germany.

"In the transition from the 20th century to the 21st century, the European mussel populations decreased by 90%, there was a huge decline in populations of this species and most likely related to human impacts," said the researcher.

With the growth of the human population, the industrialization of Europe during the twentieth century, the increase in pollution, the alteration of 'habitats' and climate change, the river mussel has become one of the “most at risk” groups.

Currently, the species is classified as Critically Endangered (CR) in Europe by the International Union for the Conservation of Nature (IUCN), and in Portugal it is only found in some rivers in the Northern region.

In this sense, the sequencing of the genome - which represents the fourth to be sequenced in about 800 species of freshwater mussels - will have “long-term implications for the preservation of the species and the conservation of ecosystems”.

“Sequencing the genome is the first step and it means that we produce the genetic information of the species. Now, we are going to have to look at that information and look for the molecular processes that control certain unique characteristics,” said the researcher.

Among the characteristics that stand out, for example, “the fact that the species produces pearls, lives for long periods or even has genes involved in the response to pollutants and the effects of climate change”.

“If the genome allows us to perceive these characteristics, it will allow us to develop methods to protect the species, which will also have implications from the point of view of ecosystems, because these species, although discrete, have important roles. For example, they have a huge filtration capacity”, he clarified.

According to André Gomes-dos-Santos, researchers from CIIMAR's Aquatic Ecology and Evolution group have now started a new project to sequence three more genomes of European species in order to “study how climate change may affect the survival of these species in Mediterranean climates ”.

"The river mussel genome now obtained will also contribute to the broader study of the impacts of climate change", he stressed.