Very Old Fantail Goldfish
How to know if fantail goldfish is slowing down/dying from old age.
What happens when fish are aging or in last year/month/days of age related death.
Grant's ReplyHi
If kept in ideal conditions, fed a variety of foods including some live, Goldfish can live for many years.
Size is a good indication of whether a Goldfish is being kept in ideal conditions. A Fantail over five years old should have a
body length of at least 4-5 inches (100-125mm).
It is not uncommon for a goldfish kept in a well set up aquarium to live 10+ years, in a pond 20+ years.
In China there are 40+ year old Goldfish!
If a Goldfish is nearing the end of its natural life, it becomes less active, sitting on the bottom frequently.
Another good indication is fin condition. The leading edges of fins become ragged on long finned varieties.
If your fish is kept in ideal conditions, and its age is approaching the maximum expected, a gradual change in diet may be helpful, especially if it presently doesn't include fresh greens or any live food.
If it has been kept in an aquarium, a spell in a pond over the warmer months where it receives natural sunlight seems to give them a boost.
Goldfish lifespans are considerably shorter if not kept in ideal conditions, 5 years in a bowl would be exceptional.
If the age of your Fantail isn't that old, but it is exhibiting the symptoms of old age, adding a little un-iodized salt to its water will give its immune system a boost.