Ever have a goldfish as a pet? The goldfish was one of the first fish to be domesticated and is a member of the carp family. Goldfish can grow up to 23 inches, weigh 10 pounds and live 4o years! Most house pet goldfish live 8 years. You can teach your goldfish tricks because they have a memory span of up to 3 months. The most common name of house pet goldfish is "Jaws".