Methuselah the Australian lungfish is one of the most famous and fascinating animals at the California Academy of Sciences. Although Methuselah was previously estimated to be about 84, the Academy has just revealed her new estimated age to be an unbelievable 92 years old, plus or minus 9 years.
Methuselah first arrived at the Academy’s Steinhart Aquarium in 1938 with another 231 fish from Fiji and Australia. At the time, the Golden Gate Bridge had only been open for one year and World War II was looming. Beloved for her sweet personality and affection for belly rubs, Methuselah has been a fan favorite through the Beat Generation, the Summer of Love, the 1989 earthquake and countless other local milestones. She resides in the Academy of Sciences’ Water Planet exhibit with two other lungfish aged 54 and 50.
When Methuselah arrived at the aquarium more than eight decades ago, there was no method for determining the age of Australian lungfish, but these days cutting-edge DNA analysis has allowed scientists to achieve a more accurate estimate. In order to develop an improved DNA age clock, Dr. Ben Mayne of CSIRO and Dr. David T. Roberts of Seqwater conducted a study of 30 lungfish from aquariums around the USA and Australia. Past aging methods have relied on more invasive and potentially lethal measures, but the new method only requires a small fin tissue sample of less than 0.5cm2.
This method has allowed Mayne and Roberts to compile a catalog of living Australian lungfish whose ages can be continually recalibrated as older lungfish became available. The new DNA age clock allows scientists to calculate the maximum age of the species, which is an essential factor for conservation efforts in the wild. It helps scientists to evaluate the species’ viability and reproductive potential.
“This research highlights the important and often serendipitous discoveries that can occur from working with public aquariums and institutions that maintain protected species in their care,” says Dr. Roberts.
“This approach to researching longevity of rare and endangered animals could be extrapolated to almost any vertebrate species, and demonstrates the value that animal care institutions such as the California Academy of Sciences can play in advancing animal knowledge to improve conservation management of species in the wild.”
Before Methuselah, the world’s oldest aquarium fish was Granddad, an Australian lungfish at the Shedd Aquarium in Chicago. Granddad lived to an estimated 109 years of age and died in 2017.
The Academy characterizes Australian lungfish (Neoceratodus forsteri) as a kind of “living fossil” being that the genus Neoceratodus has stayed essentially the same for about 100 million years. The species is native to several river systems in Queensland, Australia. Fascinatingly, Australian lungfish have a single lung that allows them to breath air at the surface when faced with low water levels or water quality.