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Bomb Curve Solves Age-Old Lungfish Problem

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Lungfish shared some traits with humans, such as the ability to breathe air through lungs, but a new study has proved that they also have a similar life span of up to 80 years.

Dr Stewart Fallon of the Australian National University said lungfish have been on the threatened species list in Australia for decades, but this new understanding could help change that. “One of the main issues is no one knew their longevity,” he said.

“A lot of fish have what’s called an otolith – basically a solid stone in their inner ear. As the fish grows, the stone grows as well, and there’s usually little annual marker bands on there, so we can count them and know how old the fish is. But the lungfish doesn’t have that stone.

“The other main issue is that to get an ear stone you usually have to kill the fish, so obviously you wouldn’t want to do that to a threatened species.”

Fallon and his collaborators came up with a new approach: measuring the amount of carbon-14 in lungfish scales to pinpoint how old the fish is. The researchers discovered they were able to place the fish on the “bomb curve”, which is used to chart the amount of carbon-14 in the atmosphere. This curve has a distinct shape, starting to rise in the mid-50s with the advent of nuclear weapons and peaking in 1963, when the Nuclear Test Ban Treaty came into effect.

“That carbon’s been...

The full text of this article can be purchased from Informit.