Deep within the tropical forests of southern Brazil, a tiny amphibian is challenging our understanding of the animal kingdom's limits. The Brachycephalus pulex, nicknamed the Brazilian flea toad, has recently been confirmed as not only the world's smallest amphibian but also the smallest known vertebrate, according to a study by biologists from Universidade Estadual de Santa Cruz.
This fascinating discovery dates back to 2011, when the Brachycephalus pulex was first identified, living isolated on a few hills in the southern region of Bahia, Brazil. Initially considered a toad due to its name, this tiny amphibian has since garnered considerable scientific interest.
To refine their knowledge on this species, researchers returned to the original discovery site, capturing and releasing several specimens after measuring them and examining signs of maturity, including the analysis of the gonads and vocal slits. This methodical approach aimed to ensure that the measured individuals were adults.
The results revealed that the average body length of the males is just over 0.28 inches (7 millimeters), with females measuring an average of 1 millimeter longer. The smallest specimen identified measured just 0.25 inches (6.45 millimeters) in length, making it about 30% smaller than the previous record held by another amphibian.
This exceptional find not only highlights the incredible biodiversity of our planet but also the mysteries yet to be uncovered. Researchers emphasize that while this is the smallest vertebrate observed to date, it is possible that even smaller creatures exist, yet to be discovered.
However, they also note that size reduction in vertebrates is limited by certain biological constraints. Morphological anomalies observed in very small frogs, such as a reduced number of toes or poorly formed ears, could compromise their survival.
This study, published in the journal
Zoologica Scripta, not only expands our understanding of biodiversity but also paves the way for future research on the adaptations and physiological limits of small vertebrate species.