The Geophagus brasiliensis, also known as the pearl cichlid or pearl eartheater, is a freshwater fish native to South America. It's a popular aquarium species, recognized for its attractive appearance and hardy nature. These cichlids can grow to be moderate in size, with males potentially reaching 25cm (9.8 in) and females slightly smaller. They are known for their territorial and aggressive behavior, especially during breeding season, and are considered a hardy species, able to survive in a range of water conditions, including brackish water and temperatures as low as 10°C.