The Oldest Living Aquarium Fish Is Ridiculously Aged

Written by Jennifer Geer
Published: September 19, 2023
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She may be 101 years old. The adorable Australian lungfish named Methuselah came to San Fransisco’s Steinhart Aquarium before World War II. 

Arriving on an ocean liner in November 1938, she quickly won the hearts of aquarium employees and the public ever since. After all, how many fish love belly rubs? Since she arrived, the oldest living aquarium fish has outlived the other 231 fishes that came with her from Fiji and Australia.

And now, we have a little more information about the beloved fish. According to a press release from the California Academy of Sciences, DNA testing has estimated Methuselah to be 92 years old (plus or minus 9 years). It was previously thought she was 84 years old.

“Although we know Methuselah came to us in the late 1930s, there was no method for determining her age at that time, so it’s incredibly exciting to get science-based information on her actual age,” said Charles Delbeek, Curator of Aquarium Projects at Steinhart Aquarium in the release. “Methuselah is an important ambassador for her species, helping to educate and stoke curiosity in visitors from all over the world.”

A New Method of Calculating Age

Researchers are excited to have developed the new method for calculating age, which they used to determine that Methuselah was 92 years old, and the oldest living aquarium fish. It’s a safer and less invasive method for the fish involved. Previous methods were more challenging and could be harmful to the fish.

“For the first time since the Australian lungfish’s discovery in 1870, the DNA age clock we developed offers the ability to predict the maximum age of the species,” Dr. Ben Mayne of CSIRO said in the release.

About the Australian Lungfish

Australian or Queensland Lungfish in aquarium

The Australian lungfish (

Neoceratodus forsteri

) is sometimes called a “living fossil.”

©Ken Griffiths/

Australian lungfish are often referred to as living fossils because they have not changed much in 100 million years. In fact, it’s known as the closest living relative to the first fish that crawled out of the sea. Unlike other fish, which use gills to breathe, the lungfish has a lung. They tend to only breathe from their lungs when water levels are low. They gulp air at the surface to supplement their oxygen. 

Carnivorous in the wild, mainly feasting on fish, frogstadpoles, and freshwater invertebrates, Methuselah’s favorite food at the aquarium is figs. But she only gets her special treat in the fall when it’s in season.

Where is the Australian Lungfish Found?

Australian lungfish

The Australian lungfish is only found in Queensland, Australia.


Other than aquariums, in the wild the Australian lungfish is only found in a few river systems in southeastern Queensland, Australia. They prefer slow-moving water systems, and they like to hide within dense aquatic vegetation. They are a slow-moving and sedentary species, rarely straying far from the place they were born.

The photo featured at the top of this post is © Ken Griffiths/

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About the Author

Jennifer Geer is a writer at A-Z Animals where her primary focus is on animals, news topics, travel, and weather. Jennifer holds a Master's Degree from the University of Tulsa, and she has been researching and writing about news topics and animals for over four years. A resident of Illinois, Jennifer enjoys hiking, gardening, and caring for her three pugs.

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