Danube an important industry. The Upper Danube ecoregion alone has about 60 fish species and the Lower Danube–Dniester ecoregion has about twice as many. Among these are an exceptionally high diversity of sturgeon, a total of six species (beluga, Russian sturgeon, bastard sturgeon, sterlet, starry sturgeon and European sea sturgeon), but these are all threatened and have largely–or entirely in the case of the European sea sturgeon–disappeared from the river. The huchen, one of the largest species of salmon, is endemic to the Danube basin, but has been introduced elsewhere by humans. Important tourist and natural spots along the Danube include
Common minke whale dwarf form in the Southern Hemisphere. This species is known in the fossil record from the Pliocene epoch to the Quaternary period (age range: 3.6 million years ago to present day). The origins of the species' common name are obscure. One of the first references to the name came in Henrik Johan Bull's account of his 1893–95 voyage to the Antarctic, when he mentioned catching a small whale "called in the Arctic language a Mencke whale, after a German who accompanied Mr. Foyn on some of his voyages." According to the British writer John Guille Millais ("The mammals of Great