What’s the lifespan of a fish is a question I get asked commonly. It’s difficult to say because it depends what fish (there are at least 4000 different species out there) and whether they’re in captivity or wild.
The common goldfish cam live for as long as 20-25 years. Sadly, many new fish keepers are unaware of new tank syndrome and many are taken much earlier, within 2-5 weeks.
The koi carp can be very long lived, at over 35 years (at a behind the scenes meet and greet, singer Gwen Stefanie mentioned she was headed somewhere to celebrate its 300th birthday!). That would definitely be the oldest fish in the world. They’re really something you can hand down over generations as an heirloom.
The Atlantic salmon can live for up to 13 years, but aquacultured fish tend to end up on your table before they reach 3 years.
The list can go on and on.
Check out this newspaper clipping –