The sturgeon is a large fish that can grow beyond two meters in length and live more than forty years. It has an elongated body with a prominent snout, mouth in ventral position and four sensory barbels. Its tail is heterocercal, and the body is covered with several rows of bony scutes, giving it a distinctive and unmistakable appearance.

Historically, sturgeons were distributed throughout the major rivers of Europe, both on the Atlantic side and in the Mediterranean and Black Sea basins. Today, only a very small population remains in the lower course of the Garonne River. In Catalonia, the species was once abundant in the Ebro River, until the construction of the Xerta dam in the 15th century disrupted its breeding migrations. Despite this, a few individuals were still observed until the decade of 1960. At present, the sturgeon is considered extinct in Catalonia.

As an anadromous species, the sturgeon migrates upstream to reproduce. Juveniles move towards the river mouths, where they stay for one or two years before migrating to the sea. Their diet includes: insect larvae, crustaceans, mollusks and small fish.

At present, the sturgeon is classified as being in critical danger of extinction worldwide. For this reason, several LIFE projects are being carried out in Europe, focusing on captive breeding programs, aimed at restoring populations and ensuring the species’ survival..