The elongated body is covered by powerful bony plates.
In the right conditions, it is believed to be able to reach several hundred kilos and live to be over a hundred years old.
Now, the mythical Atlantic sturgeon is back in Swedish waters.
It is through a release at the foot of Bohus Fortress in Kungälv, where the Göta River divides into two river arms, that a number of Atlantic sturgeons are now in Sweden again – over a hundred years after the species was wiped out.
It's the first time in 102 years that we're reintroducing an animal that was nationally extinct, says Dan Calderon, one of the initiators of the project.
Last time it concerned the beaver – which started with a pair in the Bjurälven River in northern Jämtland in 1922 and has now reached an estimated 130,000 individuals in Sweden.
Bred in Germany
The release of the Atlantic sturgeon is also starting on a small scale. Including the six first specimens on Tuesday, 100 sturgeons will be released. Most of them have been equipped with a transmitter to be followed by researchers.
To re-establish the species again requires an effort over many years, notes Dan Calderon.
Our fish come from breeding farms in Germany, where they've been working on re-planting for a long time. Their experts estimate that we need to release between 5,000 and 10,000 every year, he says.
But then you don't release them when they're this big, but when they're as big as a finger, roughly.
Hoping for a Return
During the project, it has turned out that the Atlantic sturgeon, contrary to what was previously believed, has bred in the Göta River before.
The hope is now that the sturgeons will return to spawn – in about 15 years.
When they're young, they can't tolerate saltwater, so they stay one to three years at their birthplace. But at our latitudes, a female doesn't become sexually mature until she's around 15, says Dan Calderon.
So it will probably be a protected species for a very long time, meaning that you won't be allowed to target them for fishing. But it's up to the authorities to decide.