we’ve had a fish tank with two humble goldfish for nearly ten years. soon after putting both fish the in the tank, one of the fish lost all its color which we thought little of since its not unusual for goldfish to change/shift color over their lives.

the usual explanation offered for a goldfish completely losing its color typically cites the fact that goldfish are born with fixed number of chromatophores and if the chromatophores are thinly distributed on the surface of the scales, they can lose color completely as the goldfish grows in size.

sadly, the white goldfish died a few months ago so we promptly got another brilliant orange and red companion to keep him company ( quit laughing, in the wild, goldfish swim and live in groups so why wouldn’t they want company in a tank? ).

lo and behold, after being in the tank for a few months, the new goldfish quickly and nearly completely lost all his color even though he didn’t grow substantially over that time. although it’s a small sample size, it makes me wonder if the both of the white goldfish changed their color in response to the other fish in the tank.