Reason Why an Oscar Fish Changes Color

Oscars (Astronotus ocellatus) are family Cichlidae fish that are often seen as aquarium pets. These New World cichlids are widely appreciated because they, unlike many other types of fish, often develop the ability to remember their caretakers. Other common handles for the species are marble cichlid, tiger oscar and velvet cichlid.

  1. Basic Information

    • Oscars are sizable fish, and in maturity usually grow to lengths of 8 to 14 inches. They have sturdy physiques and relatively oval forms. Most of their physical features -- mouths, eyes and heads -- are big. Oscars originated in South America, in areas such as the Orinoco river basin. Through accidental introduction in the United States, they are often a sport fish in the Florida area. Oscars have been spotted wild throughout the United States, including in Mississippi, Texas, Georgia, Arizona and Massachusetts.

    Body Coloration

    • The foundations of their narrow bodies are deep brown, grey or greenish-yellow. It's also common for oscars to have speckling of all of these colors. Their backs feature crimson stripes, and they also possess singular reddish or orange circles that are situated right by their caudal fins. Oscar youngsters have white blotting on their heads, along with corrugated orange and white bands on their bodies. Depending on the oscar's exact location, however, coloring can differ drastically within the species. The genders look extremely similar to one another.

    Color Changes in Scared Oscars

    • Oscars have the remarkable ability to lighten their body coloration -- a talent that is not uncommon within the cichlid world. This transformation in tone occurs swiftly and is believed to be a sign of apprehension. Oscars frequently "lighten up" when other creatures approach them aggressively, whether predators or even specimens of their own type.

    Color Changes in Defensive Oscars

    • Not only do oscars routinely get lighter when they're scared, they also frequently do so as a convenient defensive mechanism. When their bodies are lighter, it can be tough for others to make out the outlines of their physiques. If predators can't see that oscars are there in the first place, they won't attack them -- a pretty slick tactic.