Goldfish are among the most commonly kept and most poorly understood pets. They are intelligent, long-lived fish whose welfare needs are almost universally unmet.
Goldfish welfare is almost universally compromised in popular pet-keeping culture. The iconic goldfish bowl — too small, unfiltered, and inadequately oxygenated — causes chronic physiological stress, stunted growth, and shortened lifespan. Many goldfish live in conditions causing constant oxygen deprivation, ammonia poisoning, and temperature extremes. The practice of giving goldfish as prizes at fairs results in extremely high mortality from stress, disease, and inadequate care by unprepared recipients. A goldfish given proper care — in a large filtered tank or outdoor pond — is a long-lived, behaviorally complex companion animal.