Swimming mouse among 27 new species discovered in Peru

A webbed-legged amphibian mouse and a spotted-headed fish are among 27 new species discovered by scientists in Peru.

They were discovered on an expedition to Alto Mayo – which includes the Amazon rainforest – by scientists from the non-profit organization Conservation International and members of local indigenous groups.

Up to 48 other new species may also have been discovered, although further studies will be needed to determine whether they are new, Conservation International said.

“The discovery of so many new species of mammals and vertebrates is truly amazing, especially in such a human-impacted landscape,” said Trond Larsen, Senior Director of Conservation International.

Alto Mayo is a protected area in Northern Peru with multiple ecosystems and native territories.

It has a relatively high population density, which puts pressure on the ecology through deforestation and agricultural expansion, Conservation International said.

Yulisa Tuwi, an Awajún woman who helped with the research, said the report “allows the Awajún to protect our culture, natural resources and our territory” because it gives them a better understanding of ecosystems.

“(The Awajún) have extensive traditional knowledge of the forests, animals and plants they live side by side with,” Mr Larsen said.

The expedition also discovered a new species of dwarf squirrel, eight species of fish, three amphibians and 10 species of butterflies.

This spotted-headed fish is a new discovery for science, but the indigenous Awajún people who helped the expedition already knew of its existence.

The fish scientists were particularly shocked by its enlarged head – something they had never seen before.

This dwarf squirrel measures just 14 cm (5.5 in), half the length of the average UK gray squirrel, which ranges from 24 to 29 cm, according to the UK Squirrel Agreement.

“(It) fits so easily in the palm of your hand. Charming and beautiful maroon color, very fast,” said Larsen.

“Jumps fast and hides in the trees.”

Scientists have discovered a new species of spiny mouse – named for the particularly tough guard hairs found on their fur that function similar to the spines of a hedgehog.

They also discovered a new “amphibian mouse” that has partially webbed feet and eats aquatic insects.

It belongs to a group of semi-aquatic rodents considered to be among the rarest in the world, with the few species known to exist having only been spotted a few times by scientists.