The Blue Planet, National Aquarium Denmark, Kastrup, Denmark

The Blue Planet contains about 7,000,000 litres (1,500,000 imp gal; 1,800,000 US gal) of water divided into 53 exhibits. There are five main sections:
• The Amazon
The Amazon section is home to arowanas, pacus, freshwater stingrays, large catfish, anacondas, pale-mandibled aracaris and more. This part also has an aquarium with a big school–about 3,000–of piranhas. Near the Amazon is the smaller grotto section, with aquaria for cave tetra, various electric fish (electric eel and elephantfish) and other fish found in dark freshwater habitats.