Researchers have split what was once considered a single tree-toad species in Tanzania into four distinct species, three of them newly described. All belong to the live-bearing genus Nectophrynoides and give birth to fully formed "toadlets," a trait seen in fewer than 1% of frogs and toads. The study used museum specimens, call recordings and mitochondrial DNA (museomics) to distinguish the species. Because their ranges are smaller and more fragmented than previously thought, these toads may face greater conservation risk from habitat loss and climate change.
Three New Tanzanian 'Tree Toads' Discovered — They Give Birth to Live "Toadlets"
Researchers have split what was once considered a single tree-toad species in Tanzania into four distinct species, three of them newly described. All belong to the live-bearing genus Nectophrynoides and give birth to fully formed "toadlets," a trait seen in fewer than 1% of frogs and toads. The study used museum specimens, call recordings and mitochondrial DNA (museomics) to distinguish the species. Because their ranges are smaller and more fragmented than previously thought, these toads may face greater conservation risk from habitat loss and climate change.
05:31 AM, 11/12/2025Science
Three newly identified tree-toad species give birth to fully formed 'toadlets'
Scientists have identified three previously unrecognized species of tree toads in Tanzania that give birth to fully formed live young — commonly called "toadlets" — instead of laying eggs that hatch into tadpoles. All four species now recognized in this group belong to the genus Nectophrynoides, a rare lineage in which live-bearing occurs in fewer than 1% of known frog and toad species.
The new research, published Nov. 6 in the journal Vertebrate Zoology, re-examined hundreds of preserved museum specimens, field call recordings and mitochondrial DNA from older collections using "museomics" techniques. That combined evidence showed that what was long treated as a single widespread species, Nectophrynoides viviparus, actually comprises four distinct species in the Eastern Arc Mountains and Southern Highlands of Tanzania. Three of those species are newly described: Nectophrynoides saliensis, Nectophrynoides luhomeroensis and Nectophrynoides uhehe.
"Live-bearing is exceptionally rare among frogs and toads, practiced by less than 1% of frog species, making these new species exceptionally interesting," said H. Christoph Liedtke, a researcher at the Spanish National Research Council.
Although the newly identified species closely resemble N. viviparus at first glance, the researchers detected consistent differences in genetics, head proportions and the shape and placement of shoulder glands. The study authors also note that toads from more northern parts of the mountain chain may represent additional distinct species, pending further study.
"Some of these specimens were collected over 120 years ago," said Alice Petzold of the University of Potsdam. "Our museomics work was able to reveal exactly which populations those old specimens belonged to, giving us a lot more confidence for future work on these toads."
The taxonomic split has immediate conservation implications. Where scientists once believed one widespread species existed, they now recognize four species with smaller, fragmented ranges. That increases the likelihood that each species is more vulnerable than previously thought. The authors highlight the fate of the related Nectophrynoides asperginis, which went extinct in the wild in 2009 after habitat alteration from dam construction and an outbreak of a fungal disease.
"The forests where these toads are known to occur are disappearing quickly," said John Lyakurwa of the University of Dar es Salaam. The researchers warn that habitat loss driven by human activities and climate change could place these newly recognized species at heightened risk and call for targeted surveys and conservation assessments to determine each species' status.
What’s next? Additional fieldwork, acoustic surveys and genetic sampling across the Eastern Arc Mountains will be needed to map each species' distribution precisely, assess population sizes, and inform any necessary conservation action.