The Bornean fanged frog is named as such because it features two fang-like projections in its lower jaw.
Researchers with Michigan State University have determined that the Bornean fanged frog may be six or seven different species of fanged frog. These frogs are genetically divergent yet morphologically they can’t be distinguished. They base this assertion on DNA samples from frogs collected throughout the mountain rainforests of Malaysian Borneo. They ran the data on more than 13,000 genes across these frogs’ genomes. This analysis determined that the frogs in question are in multiple genetic clusters, with six or seven clusters classified as distinct species.
Bornean fanged frog. Photo by Chan Kin Onn et.al.
The Bornean fanged frog, known as Limnonectes kuhlii was described in the 1800s. In the last 20 years, however, genetic analysis has determined that this frog might actually be more than one species, Chan Kin Onn, curator of Vertebrate Collections at the MSU Museum told Michigan State University News. “It’s not just one species. But it’s not 18 species, either,” Chan said.
In their study, the researchers found that the frogs were also interbreeding, which can be a challenge, Chan noted, as all this “gene flow” going on can blur the DNA dividing lines and “some of the growing number of cryptic species may be more methodological artifact than biological reality,” Chan said.
“Our results show that the evolutionary histories of cryptic species can be heavily shaped by gene flow, confounding divergence estimates and phylogenetic inferences, linking evolutionary trajectories of populations, and blurring species boundaries,” the researchers wrote in their paper.
The Bornean fanged frog is named as such because it features two fang-like projections in its lower jaw. They are not true teeth and look like small tusks when the mouth is open. They are used primarily in combat with other males.
The complete paper, “A Genomic Perspective on Cryptic Species Reveals Complex Evolutionary Dynamics in the Gray Zone of the Speciation Continuum” can be read on the Systematic Biology website.
