Wild oscars are the default type of oscar fish. The original species of Astronotus ocellatus is native to the Amazon River basin, the Paraguay River, the Rio Negro and the Parana River.

Oscar (Astronotus ocellatus), a popular aquarium fish from South America. Oscar (Astronotus ocellatus), a popular aquarium fish from South America. Jón Helgi Jónsson/Wikimedia Commons/CC BY-SA 3 ...

An Asian customer spotted the markings on the astronotus ocellatus at Walker Aquatics in Waterfoot, Rawtenstall, Lancs, and offered to buy it for £10. The customer bought the most expensive tank in ...

and stress response of oscar (Astronotus ocellatus; 5.7 ± 0.8 g). Nine experimental treatments were tested, as follows: Control, Stress28 (EMS in weeks two and eight), Stress27 (EMS in weeks two and ...

Wild oscars are the default type of oscar fish. The original species of Astronotus ocellatus is native to the Amazon River basin, the Paraguay River, the Rio Negro and the Parana River.