The immeasurable diversity of flora and fauna on Madagascar makes the island nation in the Indian Ocean a Mecca for taxonomic studies. Several new species of animals continue to be found here. Now, scientists have discovered a new species of frog on the island's Montagne d'Ambre National Park.

The new species — Rhombophryne ellae — belongs to the genus Rhombophryne. Frogs from the genus are commonly referred to as "diamond frogs". While several similar looking frogs have been discovered in the past, the newly-described one has distinct markings that make its uniqueness obvious.

"As soon as I saw this frog, I knew it was a new species," said herpetologist Dr Mark D. Scherz, the author of the study, that describes the frog.

 Rhombophryne ellae
The new species, Rhombophryne ellae, is well camouflaged among the rainforest leaflitter Mark D. Scherz

Features That Make The Species Unique

The new species is closely related to a still undescribed (discovered but not formally described and named) and largely-unknown species from the Tsaratanana region of Madagascar. However, it is wholly distinct from other frogs in the diamond family.

"The orange flash-markings on the legs and the large black spots on the hip made it immediately obvious to me," said Dr Scherz, describing its uniqueness. The orange coloration on its legs makes Rhombophryne ellae the newest member of the expanding list of frogs that possess red to orange markings. However, the exact function of this distinct coloration remains a mystery.

Dr Scherz, who has studied the genus extensively, said that no other described species had such orange legs, and only a handful of them has these striking black marking son the hips. "It's rare that we find a frog and are immediately able to recognize that it is a new species without having to wait for the DNA sequence results to come back, so this was elating," he said.

Rhombophryne ellae
Rhombophryne ellae is a small, probably semi-fossorial (sub-terranean-dwelling) species of diamond frog, at home amongst the leaf litter of Montagne d'Ambre National Park, north Madagascar Mark D. Scherz

Adding To Existing Knowledge

What makes the discovery special is that the Montagne d'Ambre National Park is an extensively studied area. However, finding a new species in such a region adds to the exciting prospect of unearthing new species.

"The discovery of such a distinctive species within a comparatively well-studied park points towards the gaps in our knowledge of the amphibians of the tropics," stated Dr Scherz. He also stressed on the unusual role of adverse weather phenomenon, especially cyclones, which bring the otherwise shy creatures out of hiding.

Rhombophryne ellae
Rhombophryne ellae Mark D. Scherz

Incidentally, Rhombophryne ellae itself was caught as Cyclone Ava moved in on Madagascar. "Several other species my colleagues and I have recently described were also caught under similar cyclonic conditions," said Dr Scherz.

As the newly-described species is the sole specimen in hand, the classification of its conservation status is a challenge. Nevertheless, based on the status of other related species from the same region, it is likely that it will be Red-listed as Near Threatened on account of its micro-endemicity and small range.