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 auditory meatus, while dark or light speckling or streaking can occur along the flanks as well as what are called "tiger stripes" – "parallel, dark, usually vertical stripes". Like Bryde's whale (and occasionally blue and fin whales), dwarf minkes can exhibit auxiliary ridges on either side of the central ridge of the rostrum. Common minke whales have a disjointed distribution. In the North Atlantic, they occur as far north as Baffin Bay, Svalbard, Franz Josef Land, and Novaya Zemlya and as far south as 40°N (New Jersey) and the Hebrides and central North Sea during summer. There are a few