A second chance for conservation: lost fish species rediscovered in Bolivia

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Researchers have rediscovered Moema claudiae, a species of seasonal killifish in Bolivia that was thought to be possibly extinct. This rediscovery provides new hope for the conservation of this unique fish and the diverse wetland habitats of the region.

Colourful fish on black background.
Moema claudiae. Credit: Heinz Arno Drawert and Thomas Otto Litz.

Moema claudiae was last seen over 20 years ago in its original locality, in a site now destroyed and converted to agricultural land. Despite extensive surveys in recent years, no other living individuals had been found, and the species was deemed Critically Endangered according to IUCN criteria and thought to be possibly extinct.

However, in a recent expedition, researchers Heinz Arno Drawert and Thomas Otto Litz located a surviving population in a small, temporary pond within a remnant forest patch surrounded by farms.

Heinz Arno Drawert at the biotope where Moema claudiae was rediscovered in 2024. Credit: Heinz Arno Drawert and Thomas Otto Litz.

Published in the open-access journal Nature Conservation, this is the first record of the species in more than two decades and enabled scientists to take the first-ever live photographs, observe its behaviour, and study previously unknown aspects of its natural history.

Thomas Litz, one of the co-authors, said: “For me, it is something special to have rediscovered Moema claudiae. 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.”

  • Man standing in a wild pond.
  • Man standing in a wild pond.

The rediscovered habitat harboured not only Moema claudiae but also six other species of seasonal killifish, making it the most genetically diverse assemblage of these fish ever documented worldwide. The region’s unique ecology, where the Amazon forest meets the Llanos de Moxos savannas, appears to support this diversity, but rapid deforestation and agricultural expansion threaten these habitats at an alarming rate.

Following this discovery, scientists emphasise the urgent need to protect the area, as it is now the only known site harbouring a wild population of Moema claudiae, as well as an exceptional global hotspot for seasonal killifish diversity.

Colourful fish on black background.
Moema claudiae. Credit: Heinz Arno Drawert and Thomas Otto Litz.

Over the last 25 years, nearly 10 million hectares of forest have been lost in Bolivia, including vital wetland habitats. Deforestation has accelerated dramatically in recent years, raising serious concerns for the future of many unique species and ecosystems.

“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,” added co-author Heinz Drawert. “We cannot hope to achieve true social and economic wellbeing unless we also maintain the functionality of the ecosystems that sustain it.”

Original source

Drawert HA, Litz TO (2025) Rediscovery of a thought to be extinct beauty: a second chance for conservation. Nature Conservation 60: 115-124. https://doi.org/10.3897/natureconservation.60.160386

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