Scientists affiliated with the University of Copenhagen have formally identified and documented three novel species within the Nectophrynoides genus of tree toads, indigenous to the Eastern Arc Mountains of Tanzania.
Nectophrynoides luhomeroensis, an adult specimen in its natural habitat. The image credit is attributed to Thrane et al., with the digital object identifier 10.3897/vz.75.e167008.
The Nectophrynoides genus, a classification within the Bufonidae family, previously comprised 13 known species. These amphibians are exclusively found in the humid forests and grasslands of Tanzania.
Distinctively known as tree toads, the Nectophrynoides genus is distinguished by its viviparous reproductive strategy, a characteristic that is exceptionally uncommon among anurans.
The geographical distribution of all Nectophrynoides species is confined to the Eastern Arc Mountains, with the sole exception of Nectophrynoides viviparus, which also inhabits the neighboring Southern Highlands of Tanzania.
“These three newly identified frog species are part of a remarkable group of African toads belonging to the Nectophrynoides genus,” stated Dr. Christian Thrane of the University of Copenhagen, in collaboration with his research associates.
“Rather than the typical process of laying eggs that subsequently develop into tadpoles, the female tree toads nurture their progeny internally, ultimately giving birth to fully developed miniature toads.”
“This reproductive mechanism positions them among a select few amphibians globally that demonstrate internal fertilization and genuine ovoviviparity.”
“It is broadly understood that frogs undergo a metamorphosis from a tadpole stage, a classic biological paradigm,” remarked Dr. Mark D. Scherz from the Natural History Museum Denmark.
“However, the vast diversity of nearly 8,000 frog species encompasses a wide array of reproductive strategies, many of which deviate significantly from this widely recognized developmental pathway.”
“Only a limited number of frog species from both South America and Southeast Asia have evolved comparable reproductive adaptations, rendering these toads a rather unique occurrence in the animal kingdom.”
“The phenomenon of live-bearing is exceedingly rare in frogs and toads, with fewer than 1% of frog species employing this method, which makes these newly discovered species of particular scientific interest,” commented Dr. H. Christoph Liedtke, a researcher associated with the Spanish National Research Council.
In the course of their investigation, the research team examined 257 specimens that were initially categorized within the Nectophrynoides viviparous complex.
Based on the analytical outcomes of their study, three distinct new species were identified: Nectophrynoides luhomeroensis, Nectophrynoides uhehe, and Nectophrynoides saliensis.
“The formal description of these three new species elevates the global count of known viviparous anurans to 20 species, with 16 of these species now attributed to the Nectophrynoides genus,” the research team reported.
“The distinctive reproductive characteristics and biological traits exhibited by these bufonids underscore the profound functional loss that would result from their extinction.”
“The potential eradication of these species and the diminishment of their unique contribution to amphibian functional diversity should serve as compelling impetus to intensify conservation initiatives aimed at their preservation.”
“Further ecological surveys are imperative to achieve a comprehensive understanding of the behavior and life cycles of these extraordinary arboreal, viviparous bufonids.”
This significant discovery has been documented and published in the scientific journal Vertebrate Zoology, accessible via the following link.
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C. Thrane et al. 2025. Museomics and integrative taxonomy reveal three new species of glandular viviparous tree toads (Nectophrynoides) in Tanzania’s Eastern Arc Mountains (Anura: Bufonidae). Vertebrate Zoology 75: 459-485; doi: 10.3897/vz.75.e167008
