Newly identified Tanzanian tree-toads give birth to tiny toadlets — they skip the tadpole stage

Three Tanzanian tree-toad species discovered that bypass the tadpole stage

Scientists have identified three new species of tree toad from Tanzania that use a highly unusual reproductive strategy: instead of hatching into free-swimming tadpoles, females give birth on land to tiny, fully formed toadlets only a few millimeters long.

The species descriptions appear in a study published this month in Vertebrate Zoology. Until now, these forms were treated as a single species. Researchers separated them after comparing genetic sequences, recordings of male advertisement calls, and detailed morphological traits, concluding that they represent three distinct species within the same genus.

To reach their conclusions, the team examined 257 specimens held in five European museum collections, some of which were collected more than 100 years ago. The study combined traditional morphological study with DNA extraction and analysis and sound recordings to delimit the new species.

The authors note that live birth (viviparity) or direct birth of fully formed young is extremely rare among amphibians and is recorded in fewer than 1% of species. Finding multiple closely related species with this trait highlights both the diversity of reproductive strategies in amphibians and the importance of museum collections for understanding biodiversity.

Significance: These discoveries improve understanding of amphibian evolution and may have implications for conservation, since specialized reproductive modes can be vulnerable to habitat change. The research underscores how combining genetics, bioacoustics, and museum specimens can reveal hidden species diversity.

Study reference: Vertebrate Zoology (published this month).