A pair of goldfish called Shaggy and Daphne survived 134 days without food or a water filter for their tank after the Christchurch building they were in was designated off-limits following February's major earthquake.
The devastating 6.3-magnitude quake killed 181 people and caused significant structural damage in the city's downtown area.
The two goldfish, named after Scooby Doo characters, were found alive when one of the employees at the accountancy office which featured them in its lobby was allowed to return and collect personal belongings on July 6, the AP reports.
Quantum Chartered Accountants company director Vicky Thornley says she was "astounded" to discover there was still life in the tank after over four months without food.
Paul Clarkson of the Monterey Bay Aquarium in California says it is likely that the fish survived by living off of weeds in their 26-gallon tank, while natural bacteria could have kept the water clean enough for their survival.
Less fortunate were four other fish who had been in the tank at the time of the earthquake. There was no sign of three of them when Shaggy and Daphne were rescued, while the remains of a fourth floated in the tank.
The two surviving goldfish have been relocated to Thornley's home.