After a five year expedition into the Brazilian cloud forests, researchers found seven new species of a tiny frog that can easily win the world’s smallest frog contest. The new species were discovered on seven separate mountains located in Brazil’s Atlantic rainforest
The newly-found critters grow up to 3 inches (1 centimeter), wear flashy colors, and have their skin covered with a poisonous toxin called tetrodotoxin that keeps predators at bay.
A paper on the discovery was published this week in the journal PeerJ.
Marcio Pie, the lead-author of the find and professor at the Federal University of Parana in Brazil, said that expeditions were “really exhausting” since the trails on the mountains he had to climb were not clearly marked. Most of the peaks his team explored were not higher than 5,000 feet (1.500 m)
Prof. Pie was also surprised by the biodiversity of the species that dwell in the Brazil’s cloud forests. He explained that those forests host more species of plants and animals than any other place in the Amazon.
The team noted that the tiny frogs which were classified under the Brachycephalus genus are very sensitive animals that can suffer from even the tiniest temperature variation in their environment.
That’s the reason why, the seven species live on seven mountain peaks separated by warmer valleys. The temperatures in the valleys prevented the frogs from traveling from one mountain to another.
There are currently 28 species of Brachycephalus frogs in the world most of them living in Brazil’s cloud forests.
The minuscule animals are also very different from other frog species. Besides their colorful skin and unique defense mechanism, they also hold three toes instead of five and two fingers instead of four like most frogs do. They also have a poor ability to jump.
Researchers reached the conclusion that the seven frogs were from seven different species because of the tone and texture of their skin. They explained that the brighter the color, the more poisonous their skin was. Frogs also had variations in roughness and bumpiness of their epidermis.
But finding the new species was the biggest challenge. The team had to look for the thumbnail-sized frogs under the leaf litter for hours, and there were days when they came back empty handed at the end of the day.
Scientists were guided by the noises the little critters were making, but getting hold of one of them was very frustrating since the animals are experienced hiders.
“You can hear them singing and there’s probably hundreds of them, but you simply can’t catch them!,”
Prof. Pie said.
He explained that once you get closer to them they sense the vibrations of the ground and remain silent for 20 minutes up to half an hour.
Image Source: BBC