The heart-warming news for animal lovers! A few species of frogs which were last seen 100 years ago have been spotted again.

A flourescent green frog with ash-blue thighs and black pupils with patches of gold last observed 136 years ago is among five lost amphibians from India rediscovered by zoologists.

The zoologists from several academic institutions searching India’s forests for amphibians documented in the past but unseen for decades have rediscovered five frogs, including the Chalazodes bubble-nest frog last reported from Travancore in 1874.

“It’s got a colour combination I have never ever seen in 27 years of studying amphibians,” said Sathyabhama Das Biju, a zoologist at Delhi University, who is also the coordinator of the nationwide search for lost amphibians.

The Indian effort was part of a search for missing amphibians in 21 countries launched in August last year by the non-governmental body Conservation International and the International Union for Conservation of Nature.

Biju and two Bangalore-based conservation researchers R. Ganeshan and K.S. Seshadri found the Chalazodes bubble-nest frog in the forests of Kodayar near the Kalakkad Tiger Reserve in Tamil Nadu on a November night.

As they walked in the dark with torchlights using sticks to lift clumps of bushes, they were drawn to a cluster of bamboo reeds by the call of what sounded like a frog. A few minutes later, they spotted it on the reed about five feet above the ground.

“It is a secretive animal — it spends most of its time hiding inside the bamboo reeds. It comes out during breeding but lays eggs inside the reeds,” Biju told The Telegraph. The scientists observed one juvenile and three adults.

A British herpetologist had documented the species from Travancore in 1874, Biju said. Scientists believe this frog does not have a free-swimming tadpole stage, but completes development inside the egg.

The amphibian search has also yielded the Anamalai dot frog, the Dehradun stream frog, the Silent Valley tropical frog, and the Elegant tropical frog — each of which had last been observed decades ago and were classified as missing.

“Our knowledge of what we have to conserve is poor. Searching for lost species is an important step towards understanding what we have left to conserve. If we want to save frogs, we first have to find them,” Biju said.