Oscar Fish Care: The Complete Beginner's Guide to Keeping, Feeding, Breeding, and Maintaining Healthy and Thriving Oscar Fish in a Home Aquarium Are you fascinated by the bold personality and intelligence of Oscar fish (Astronotus ocellatus)? These large and colorful cichlids are among the most popular freshwater aquarium species for good reason. Known for their charisma, interactive behavior, and beautiful coloration, Oscars make excellent centerpiece fish-but only when given the right environment. This beginner-friendly guide walks you through everything you need to know to keep your Oscar fish happy, healthy, and thriving-from tank setup and diet to breeding and tankmate selection.