A newly discovered glass frog species whose beating heart is visible through its chest is already feared to be in danger, because its habitat is threatened by oil exploitation.

The frog (Hyalinobatrachium yaku), identified through a combination of fieldwork in the Amazonian lowlands of Ecuador and DNA sequencing in the lab, displays unique physical and behavioural traits.

The dark green spots on its back and its call and reproductive behaviour mark it out as different from already known frogs.

“Males guard the eggs, which are attached below a tree’s leaves, until they hatch and fall on the below water stream,” says Juan Guayasamin, of the Universidad San Francisco de Quito, in Ecuador. “I work with frogs every day and this is one of the most beautiful species I have ever seen.”

“Not all glass frogs have hearts that are visible through the chest. In some, the heart itself is white, so you don’t see the red blood,” says Paul Hamilton, of US non-profit organisation the Biodiversity Group.

Hyalinobatrachium yaku is a newly discovered glass frog

Jaime Culebras

Under threat

It’s not known why different species have different levels of transparency, but this frog “will help us understand the evolutionary pattern that led to frogs being glass-like”,

“Amphibians are the most threatened vertebrate class on the planet,” says Ariadne Angulo of the amphibian specialist group at the International Union for Conservation of Nature. “The group’s species richness has not been fully discovered yet. Since 2005, we have been identifying between 100 and 200 new amphibian species per year.”

Far fewer new mammals and birds are discovered, because a higher proportion of species have already been described, says Angulo. However, she adds, “because there are so many undiscovered amphibian species out there, given our current rate of environmental degradation, some may become extinct before we even know them”.

Glass frogs need pristine streams to breed. “If the stream dries up, or becomes polluted, the frogs can’t survive, and other more resilient creatures may be next,” notes Hamilton.

We don’t yet know enough about the new species to establish whether it is would be officially deemed as threatened. “We do know, however, that its habitat is rapidly disappearing. Oil production has expanded greatly in this species’ range, and road building is rampant,” says Hamilton.

He fears that these issues will get much worse. “We hope that discoveries like this glass frog can help raise awareness of what more there is to be lost with continued fossil fuel extraction, apart from what we already know about climate change,” he says.