Oscar (Astronotus ocellatus)
The oscar is a species of freshwater cichlid native to the Amazon River basin in South America. The fish grows up to 45 cm (18 in) and is popular in the aquarium trade. Several morphological variations, such as albino and long finned varieties have arisen due to selective ornamental breeding.
Jón Helgi Jónsson on wikimedia commons, Daniella Vereeken on Flickr