The World’s Smallest Vertebrate – A Tiny New Guinean Frog

Researchers from Louisiana State University have discovered the world’s new smallest vertebrate, a frog so small you could fit two on a dime end-to-end. From National Geographic:

The world’s smallest known vertebrate is a frog the size of a housefly, a new study says.

At an average of 7.7 millimeters long, the newfound Paedophryne amauensis is a hair smaller than the previous record holder, the Southeast Asian fishspecies Paedocypris progenetica, whose females measure about 7.9 millimeters…

It’s obvious “they’re adapting to fill a niche that nothing else is filling,” he said.

Indeed, the frogs likely evolved their tiny sizes to eat tiny invertebrates, such as mites, that are ignored by bigger predators, said study co-author Christopher Austin, a biologist at Louisiana State University in Baton Rouge…

Scientists locate the teensy animals by listening for their calls and trying to zero in on the sources of the sounds—no mean feat, since the high pitch of the calls make their sources especially hard for human hearing to locate.

Austin and graduate student Eric Rittmeyer tried four times to find the frogs before exasperatedly grabbing a big handful of leaf litter and putting it in a plastic bag.

The scientists then combed through the contents until “eventually we saw this tiny thing hop off one of the leaves,” Austin said.

The frogs are so small it’s hard to see their earth-colored skin patterns with the naked eye, so Austin took pictures and then zoomed in, using a digital camera like a microscope.

But photographing the amphibians was just as challenging as finding them. When Austin brought the camera to his eye, the subject would often already be gone.

The new frogs are “incredibly good jumpers—they can jump 30 times [longer] than their body size,” said Austin, whose study was published January 11 in the journal PLoS ONE.

That’s pretty incredible; there are some organisms that seem to straddle the boundaries between different worlds, and this is one of them. I want a report back from this frog on what life in the insect world is like. 

Photograph by Christopher Austin, via National Geographic