The Danube salmon can reach the size of a man and live for 30 years — but its last hunting grounds in the Balkans are being threatened by a rash of dam-building.
"It's very fast, lean, and elegant. And very beautiful," Ulrich Eichelmann. director of the environmental group Riverwatch, told BBC News.
Hucho Hucho in Latin, Huchen in German, often known as the Danube salmon in English because it was once found in much of the Danube basin.
But its main remaining refuge today is in the Balkans, in the streams and rivers which tumble down the mountains and twist through the valleys between Slovenia and Montenegro.