Confirmed: PNG home to world’s smallest vertebrate – a frog

National, Normal

The National,Monday16 January 2012

IT is confirmed. Papua New Guinea is home to the world’s smallest vertebrate with the discovery of a new species of frog that is so small two of them could `squeeze’ onto a dime (US 10-cent coin).
The world’s leading media, including Time magazine, CNN news, the BBC,  Fox News, USA Today and number of internet news websites have reported the discovery of Paedophyrne amauensis which averages about 7.7mm long.
The new species is related to the Paedophryne dekot and Paedophryne verrucosa species which, last December, were identified as the smallest frogs in the world.
Both are also found in Papua New Guinea.
P. dekot inhabits the lower ranges, below about 1,200m of the western slope of Mt Dayman in Milne Bay and P. verrucosa lives on the southeastern slope of Mt Suckling near a region that joins Mt Dayman.
But compared with P. amanuensis, they average a “massive” 8.1mm to 9.3mm in size.
A team of American researchers from Louisiana State University in Baton Rouge discovered the frog in the jungles of PNG in 2009.
The creatures are named after a Central village called Amau, which is near where they were found.It was only last week that the science journal, PLoS One, dubbed the frog with the teeny-tiny honour.
The frog beats the previous record for a tiny Indonesian fish (paedocypris progenetica) which average 7.9mm in length. 
The tiny frogs are difficult to see but can be easily heard as they have high-pitched calls which make them sound like crickets.
Prof Chris Austin was part of the team that discovered the frog on a three-month field trip to Amau.
These creatures make their habitats on fallen leaves on the floor of tropical rainforests.
“After several failed attempts to find it, we ended up just scooping up a big handful of leaf litter where the call was coming from and putting it all in a clear plastic bag,” Austin said.
After sorting through the bag leaf by leaf, they “discovered the incredibly small frog making the call”.
The creatures will help scientists understand more about extreme body size.
The frogs are thought to have evolved “extreme miniaturisation” to fill a hole in the food chain which was not being exploited by others, perhaps to eat minuscule creatures such as mites unable to sustain larger frogs.
“We now believe they aren’t just biological oddities, but instead represent a previously undocumented ecological guild – they occupy a habitat niche that no other vertebrate does,” Austin said.
“(Papua) New Guinea is a hotspot of biodiversity, and everything new we discover there adds another layer to our overall understanding of how biodiversity is generated and maintained,” Austin adds.
Steven J. Beaupre, from the University of Arkansas and president-elect of the American Society of Icthyologists and Herpetologists, said that the discovery was a boon for scientists. He said the new species would help scientists better “understand the advantages and disadvantages of extreme small size and how such extremes evolve”.
“Fundamentally, these tiny vertebrates provide a window on the principles that constrain animal design.”