Racing Bulldozers: FIU biologist helps discover four new frog species

Science can’t study a species — or unlock its potential to change the world — until people actually know it exists. Four new species of frogs have now been given names, thanks to the efforts of FIU biologist Alessandro Catenazzi.

The researcher in the FIU Institute of Environment and his collaborators used morphological, acoustic, and genetic evidence to describe four new species of Oreobates frogs collected near the Cordillera Azul National Park in Peru, raising the known number of species of these small, ground-dwelling frogs from 27 to 31. The research was published recently in the journal Diversity.

Catenazzi, a veteran biologist who has contributed to the description of more than 55 frog species throughout his career, says the importance of naming a species goes far beyond adding another entry into a scientific catalog.

“Each species is its own world,” said Catenazzi. “We derive a lot from nature — even drugs, even food. I can’t tell you specifically what the value of these four species is yet, but there could be a cure for cancer there … And the first step of anything you want to do in biology is to name the organism.”

Giving a frog a name may sound simple, but establishing that it is actually a new species is far from it. For Catenazzi and his collaborators, that process involves comparing physical traits, calls, and ultimately genetic evidence.

“You can be very knowledgeable about what you see in the forest, but you also have to know what people have already described. And that’s not trivial, because a lot of those species were described in the 19th or 20th century. The types are often at the British Museum, or in some European museum, or in New York or at the Smithsonian. It can be challenging, because just to have seen the types means going to all those places and actually handling them.”

But checking museum specimens only answers whether a frog has already been morphologically described. Biologists like Catenazzi still needed to determine whether the four specimens collected were distinct from their closest relatives.

“We still look at morphological traits that will differentiate them — this one is black, this one is brown, this one has a little tubercle, this one has smooth skin, and so on,” he said. “But in addition to that, we also look at the [mating] calls. We record the calls and we characterize them, we contrast them. And that’s very useful because females are not going to be attracted to a call that does not come from their own species.”

For some frogs, the differences are much harder to observe, making genetic analysis another crucial piece of the puzzle. Using DNA sequences, he reconstructs the evolutionary history and creates a sort of family tree for the species.

But the biologists don’t need to sequence every part of the new frogs’ entire genomes. Instead, they compared specific pieces of DNA which have already been sequenced for many other frog species.

Combined with the morphological and call differences, the genetic evidence supported recognizing the four frogs as distinct.

While the potential of these four newly discovered species remains unknown, Catenazzi’s lab is actively working with two other species of frog that have unique peptides with antimicrobial, wound healing and antifungal properties. Discoveries like those illustrate why Catenazzi believes frogs can become powerful tools for justifying protected areas to prevent further habitat destruction.