The flea toad, a minuscule amphibian with a body size smaller than a pea, is considered the tiniest frog and vertebrate species in the world. Initially referred to as toads, the flea toad was only identified in 2011 in Brazil’s Serra Bonita mountain range. Researchers have measured enough of these tiny leaf-litter-patterned frogs to confirm that their small size was not a fluke. The flea toad has surpassed the Paedophryne amauensis, which previously held the record for being the smallest vertebrate species.
The adult male flea toads have an average body size of around 7.1 millimeters, while the females tend to be slightly larger (with an average of 8.15 millimeters for B. pulex). This is probably due to the need to fit a bunch of developing eggs inside their bodies. Being small has its advantages, such as requiring less food and being harder for predators to find. However, there are also drawbacks. According to a 2022 study, animals with internal skeletons (vertebrates) have physical limitations, and it becomes difficult to produce enough vital organs, including a large vertebrate brain or enough eggs for a sustainable population, once their size is below 6 millimeters.
The flea toad has lost some of the common frog features, such as the ability to jump or hear their own species’ love songs, due to its confined body plan. Moreover, the flea toad’s limbs have not enough space for standard amounts of fingers and toes. They are missing their first and fourth fingers, leaving only a long third finger, shorter second finger, and a vestigial fifth finger. The flea toad has only two hard bony parts: their spine and skull and everything else is softer cartilage.
The flea toad’s ears are underdeveloped, and researchers have not observed them making any form of vocalization. Despite all these limitations, the flea toad manages to survive by stalking tiny prey in the dense leaf litter and epiphytes of their mountainous forest homes.
This news is a creative derivative product from articles published in famous peer-reviewed journals and Govt reports:
References:
1. Bolaños, W. H., Dias, I. R., & Solé, M. (2024). Zooming in on amphibians: Which is the smallest vertebrate in the world?. Zoologica Scripta.
2. Almeida-Santos, M., Siqueira, C. C., Van Sluys, M., & Rocha, C. F. D. (2011). Ecology of the Brazilian flea frog Brachycephalus didactylus (Terrarana: Brachycephalidae). Journal of Herpetology, 45(2), 251–255.
3. Bornschein, M. R., Ribeiro, L. F., Blackburn, D. C., Stanley, E. L., & Pie, M. R. (2016). A new species of Brachycephalus (Anura: Brachycephalidae) from Santa Catarina, southern Brazil. PeerJ, 4, e2629.
4. Bornschein, M. R., Ribeiro, L. F., & Pie, M. R. (2021). Reassessing overlooked information about the diagnosis of Brachycephalus atelopoide (Anura: Brachycephalidae), a neglected problem for the taxonomy of the genus. Phyllomedusa, 20, 109–115.
5. Campos, L. A., Da Silva, H. R., & Sebben, A. (2010). Morphology and development of additional bony elements in the genus Brachycephalus (Anura: Brachycephalidae). Biological Journal of the Linnean Society, 99(4), 752–767.