Scientists have rediscovered Moema claudiae, a seasonal killifish long thought extinct, in a small temporary pond in Bolivia. The species, unseen for over two decades due to habitat loss, was found in a forest fragment amid farmland. This discovery highlights both conservation hope and the urgent threats facing wetland ecosystems.
The rediscovery of Moema claudiae marks a rare bright spot in global conservation efforts. First described decades ago and named after the wife of ichthyologist Prof. Wilson Costa, the tiny fish had vanished from records since the early 2000s. Its original habitats in Bolivia were converted to farmland, leading to its classification as Critically Endangered by the IUCN and fears of extinction.
In a recent field expedition, researchers Heinz Arno Drawert and Thomas Otto Litz located a surviving population in a remote, temporary pond nestled within a shrinking forest patch surrounded by agricultural fields. This is the first confirmed sighting in more than 20 years, detailed in a 2025 paper in the journal Nature Conservation. For the first time, scientists photographed the fish alive and observed its behavior, revealing new insights into its ecology.
Thomas Litz, a co-author, called the find personal and profound. "For me, it is something special to have rediscovered Moema claudiae," he said. "This has shown that we now have the opportunity to preserve this species in the wild. I am all the more pleased because Prof. Wilson Costa named this species after his wife Claudia, and I would like to take this opportunity to thank him especially for decades of collaboration and support."
The site proved even more significant, hosting six other seasonal killifish species—the most diverse such assemblage documented worldwide. Located at the junction of the Amazon forest and Llanos de Moxos savannas, the area supports exceptional biodiversity. Yet, threats loom large: Bolivia has lost nearly 10 million hectares of forest in the past 25 years, with deforestation accelerating.
Co-author Heinz Drawert urged swift action. "Without rapid and effective action to curb the irrational expansion of the agricultural frontier in Bolivia's lowlands, we risk losing some of the world's most important terrestrial and aquatic ecosystems, and with them the irreplaceable goods and services they provide," he warned. "We cannot hope to achieve true social and economic well-being unless we also maintain the functionality of the ecosystems that sustain it."
This single known site for Moema claudiae underscores the need to protect these fragile wetlands before they disappear.
