For over a century, the frog species Alsodes vittatus was thought to be lost to history, unseen since its original discovery in Chile in 1894. But now, in a remarkable turn of events, scientists from Chile have rediscovered this elusive amphibian in the Andean foothills of Chile’s La Araucanía Region.
A recently published study in the journal ZooKeys reported this rediscovery, reviving interest in the species and raising questions about its conservation status and evolutionary history.
Through field surveys and genetic analysis, the researchers confirmed the identity of A. vittatus, shedding new light on the diversity of Chile’s amphibians and the importance of preserving their fragile ecosystems.
Study: Lost for more than a century: the rediscovery of Alsodes vittatus (Philippi, 1902) (Anura, Alsodidae), one of the rarest and most elusive amphibians from Chile. Image Credit: Lwhirlpool/Shutterstock.com
The Elusive Alsodes
Amphibians play a crucial role in maintaining ecosystem health, yet many species remain poorly understood, particularly in remote and mountainous regions. In Chile, historical taxonomic records have been clouded by uncertainty, with numerous species being misidentified or declared extinct due to a lack of sightings.
The Alsodes genus is a group of frogs native to the Andes and has long been a focus of conservation efforts. Many species within this genus are found in isolated habitats, making them vulnerable to environmental changes and human activities.
Furthermore, no confirmed sightings of A. vittatus had been made for 130 years, leading scientists to believe it had disappeared.
However, herpetologists and naturalists continued the search to establish whether this species was truly extinct or hidden in an unexplored corner of the Andes.
The recent discovery of new populations of A. vittatus challenges long-held assumptions of its extinction and underscores the need for continued biodiversity research in Chile’s high-altitude forests.
The Search of Alsodes Vittatus
To locate the lost A. vittatus, the team of Chilean researchers conducted extensive field surveys in the Andean foothills, focusing on areas historically linked to the species’ original discovery.
The team explored multiple sites, carefully documenting environmental conditions, amphibian populations, and potential microhabitats where A. vittatus might survive.
Their search led them to five previously undocumented localities, three of which were confirmed to harbor populations of the species.
Once specimens were collected, the researchers employed genetic analysis to confirm their identity. Tissue samples were taken from various developmental stages, including adult frogs, juveniles, and tadpoles.
Deoxyribonucleic acid (DNA) extraction was performed, and mitochondrial gene sequencing was used to compare the rediscovered frogs with known species of the Alsodes genus.
Additionally, morphological analysis was conducted to examine key physical traits. The researchers noted variations in dorsal coloration and the presence of a distinctive vertebral line in some individuals, which had been a defining feature of A. vittatus in its original description.
However, the study confirmed that this trait was not exclusive to the species and varied between individuals. The frogs were observed in high-altitude streams with rocky beds, surrounded by native Nothofagus or southern beech and evergreen coniferous Araucaria forests, highlighting the species’ dependence on specific microhabitats.
Major Findings
The study found that A. vittatus, long thought to be extinct, still survives in at least three separate locations in Chile’s La Araucanía Region. These newly identified populations were found in high-altitude forested streams, where researchers documented juveniles, adults, and tadpoles.
Furthermore, the phylogenetic analysis revealed that A. vittatus is closely related to A. neuquensis, and the two species may, in fact, be a single taxon, challenging previous assumptions about their classification.
Morphological data showed significant variation in the frog’s coloration, with only some individuals displaying the species’ signature vertebral line.
This suggested that the presence of the line is a polymorphic trait rather than a defining characteristic of the species. Additionally, variations in size, skin texture, and toe webbing were observed, further complicating the taxonomic distinctions within the Alsodes genus.
From a conservation perspective, the researchers determined that A. vittatus should no longer be classified as Critically Endangered but rather as Endangered. While the rediscovery is encouraging, the species faces ongoing threats from habitat destruction, climate change, and the presence of invasive predators such as trout in Andean waterways.
The frogs’ habitats are also under pressure from human activities, including deforestation, livestock farming, and potential impacts from tourism.
One limitation of the study is the small sample size, which prevents definitive conclusions about population stability and genetic diversity.
The researchers believe that extensive explorations in the region will be needed to determine whether these populations are stable and whether additional undiscovered groups exist in other parts of the Andes.
Conclusions
Overall, the rediscovery of A. vittatus after more than a century is a testament to the resilience of nature and the value of persistent scientific exploration.
This finding not only reshapes our understanding of amphibian diversity in Chile but also underscores the urgent need for conservation efforts.
Protecting the fragile habitats of these elusive frogs and similar rare species is critical to ensuring their survival in a rapidly changing world.
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