Taxonomists are racing against the clock to discover and catalogue new species before they become extinct. It will allow us to protect the planet’s remaining biodiversity. But major advances are required to complete the biological inventory on Earth.
An international team has now made significant progress in the taxonomy of Madagascar’s frogs. They had named 20 new species all at once. The article was published in the open-access journal Megataxa.
The frogs are from the subgenus Brygoomantis of the genus Mantidactylus. This place previously had only 14 species. These small and brown frogs are common along streams in Madagascar’s humid forests. But they are difficult to spot. To attract females, the males make very subtle advertisement calls.
“The calls typically sound like a creaking door or a gurgling stomach,” explains lead author Dr. Mark D. Scherz, Curator of Herpetology at Denmark’s Natural History Museum. “Finding, recording, and capturing calling individuals of these frogs is difficult. But it has proven critical for the discovery and description of many new species. That means spending a lot of time on your hands and knees in the mud.”
In a cutting-edge technology named “museomics,” DNA is sequenced from old museum material. It was a key tool in the authors’ arsenal. This is frequently difficult because DNA degrades over time and as a result of the various chemicals used to preserve animal specimens. Scientists have also used a technique known as “DNA Barcode Fishing“. With this technique, the team was able to obtain usable DNA sequences from the majority of the relevant museum material.
“Museomics gave us a level of confidence in our species descriptions that was not previously possible based on morphology alone,” says senior author Professor Miguel Vences of the Technische Universität Braunschweig.
Even this significant advancement does not appear to be the final word on the subgenus Brygoomantis. “There are still several Brygoomantis lineages that are probably separate species. But for which we didn’t have enough data or material,” says Dr. Andolalao Rakotoarison, co-chair of Madagascar’s Amphibian Specialist Group.
“Even for the species that have names, we know very little about their biology or ecology. We need a lot more field research on these frogs. We also need more specimens in museum collections to truly understand them.”
More information: D. SCHERZ et al, An inordinate fondness for inconspicuous brown frogs: integration of phylogenomics, archival DNA analysis, morphology, and bioacoustics yields 24 new taxa in the subgenus Brygoomantis (genus Mantidactylus) from Madagascar, Megataxa (2022). DOI: 10.11646/megataxa.7.2.1
