Freshwater fish - Artensterben

The Sepik in Papua New Guinea: The spinach pipefish, missing for decades, was rediscovered in this sprawling river system in 2026. Image: David Bacon, CC BY 2.0, via Wikimedia Commons

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2. September 2026 Doreen Fräßdorf

Spinach Pipefish Rediscovered After More Than 40 Years

For more than four decades, the spinach pipefish (Microphis spinachioides) had not been scientifically documented. Known only from Papua New Guinea, this freshwater fish belongs to the pipefish family and is therefore related to seahorses. In June 2026, the long-lost species resurfaced: On the lower Sepik, New Guinea’s longest river,

Atlantic salmon (Salmo salar). In Hamburg, the species is considered threatened with extinction. Image: Depositphotos (collaboration)

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27. August 2026 Doreen Fräßdorf

New Red List: One in Three Native Freshwater Fish and Cyclostome Species in Hamburg Is Threatened

Hamburg is not only a port city, but also a city of waterways. The Elbe, Alster, and Bille rivers, along with numerous streams, canals, tidal channels, and marsh waters, provide habitat for a diverse community of fishes and cyclostomes. However, the new Red List of Hamburg’s Freshwater Fishes and Cyclostomes

With the 2026 IUCN update, the brush-tailed bettong (Bettongia penicillata), which has not been recorded since the 1920s, is listed as extinct for the first time. Whether Lydekker's 1896 illustration actually depicts this species remains unclear because B. penicillata and B. ogilbyi were not distinguished until later. Image: Lydekker, Richard, Public domain, via Wikimedia Commons

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12. July 2026 Doreen Fräßdorf

2026: IUCN lists 15 more animal species as extinct

The IUCN has updated its Red List. Version 2026-1, published on July 9, 2026, lists a total of 15 more animal species in the “Extinct” (EX) category: six mammals, four fish, one insect species, and four snail species. Most of these are not recent extinctions; many of the species disappeared

Europäische Süßwasserfische - Plötze und Rotfeder (Heinrich Harder / Emil Walter)

Historic depiction of European freshwater fish (Heinrich Harder)—the new IUCN Red List (2025) shows how severely the condition of European waters has deteriorated. Image: Walter, Emil, Public domain, via Wikimedia Commons

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17. April 2026 Doreen Fräßdorf

IUCN Red List 2025: Europe’s freshwater fish in crisis—nearly 60% under pressure

Europe’s rivers and lakes are among the most heavily altered ecosystems in the world. Hardly any body of water remains unaffected—many have been regulated, dammed, or fundamentally transformed by human use. The updated IUCN Red List (2025)—the most comprehensive assessment of European freshwater fish in 15 years—makes the consequences of

Bodensee-Kilch (Coregonus gutturosus) und ein Tiefseesaibling (Salvelinus profundus)

Historic depiction of the Lake Constance whitefish with the Lake Constance deepwater char (bottom left), which was rediscovered in 2016. Both lived in the deep areas of Lake Constance — a habitat that was severely affected by eutrophication in the 20th century. (© Walter, Emil, Public domain, via Wikimedia Commons)

Fish

15. April 2026 Doreen Fräßdorf

Lake Constance Whitefish: An example of species loss in alpine lakes

Species or just a form? The Lake Constance whitefish or kilch belongs to the genus Coregonus—a group of salmonids found in cool, oxygen-rich waters across the Northern Hemisphere. In Europe, they are known as Felchen, Maränen, Reinanken or Renken (whitefish). Hardly any other fish group is considered as taxonomically difficult: many forms have arisen only

Flusspferd als eingeschleppte Süßwasser-Megafauna

Hippopotamus – This mammal, weighing up to three tons, is one of the largest freshwater inhabitants on Earth. In Colombia, feral populations exist today after animals escaped from a private collection and spread along the Magdalena River. (© Joachim Huber, CC BY-SA 2.0, via Wikimedia Commons)

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10. March 2026 Doreen Fräßdorf

Introduced freshwater megafauna: Benefits and risks of large animals in rivers and lakes

Rivers and lakes are home to some of the largest animals in inland waters—from giant catfish, sturgeons, salmon, and carp to turtles and crocodiles. However, many of these species have been deliberately introduced by humans into new regions. A new global study in the journal One Earth systematically examines for

Qutang-Schlucht am Jangtse (Changjiang) in der Drei-Schluchten-Region in China

The Qutang Gorge on the Yangtze (Three Gorges region): heavily burdened for decades—a study now shows the first signs of ecological recovery. (© Tan Wei Liang Byorn, CC BY 3.0, via Wikimedia Commons)

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21. February 2026 Doreen Fräßdorf

Hope for the Yangtze: study shows how a fishing ban is reviving the river

The Yangtze River is Asia’s longest river at over 6,300 kilometers and the third-longest river in the world. For millennia it was among the world’s most species-rich freshwater ecosystems. It supplied people, animals, and entire cultures with water, food, and habitat—and formed the ecological backbone of large parts of China.

Wiederentdeckung: Killifisch Moema claudiae

Tiny, vividly colored and almost lost: Moema claudiae — shown here as a male (top, 3.8 cm) and a female (bottom, 3.6 cm) — was rediscovered in 2024 after more than 20 years. This killifish species grows to only about four centimeters and survives in temporary rainy-season pools of the Bolivian Amazon region. (© Drawert & Litz (2025), Nature Conservation, CC BY 4.0)

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17. November 2025 Doreen Fräßdorf

“Lost Beauty”: Fish thought extinct rediscovered after 20 years

When researchers examined an inconspicuous, shallow pond on the edge of a remote remnant forest in Bolivia in spring 2024, they had no idea that right there—beneath leaves, gray mud and surrounded by vast agricultural land—they would find a species many already believed to be extinct: Moema claudiae, a seasonal

Lipochromis (Haplochromis) microdon Wiederentdeckung

Haplochromis microdon, an endemic cichlid from Lake Victoria, was considered lost for decades. The species can reach a length of up to 14.8 cm and is one of the specialized fish fry predators in the lake's ecosystem. (© Dr. Anna Mahulu, Institute of Ecology and Evolution, University of Bern)

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11. May 2025 Doreen Fräßdorf

Lost in Lake Victoria: Cichlid Haplochromis microdon rediscovered after 40 years

For decades, it was considered lost—perhaps even extinct. But now there is new hope for Haplochromis microdon, an endemic cichlid species from Lake Victoria: As reported by the organization SHOAL in an article by Anna Mahulu, the species was detected for the first time since 1985 during targeted research expeditions

The first photograph of the snakehead fish Channa amphibeus. The species was already considered extinct after it had not been recorded since the early 20th century. (© Photo Credits: X/ @ranjeetnature)

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1. February 2025 Doreen Fräßdorf

India: Lost Borna snakehead rediscovered after 85 years

The Borna snakehead Channa amphibeus, also known as the Chel snakehead, has been rediscovered in India’s Himalayan region. The species was regarded as one of the rarest and hardest-to-find snakehead species in the world, and scientists had already suspected that it was extinct. A research team led by Jayasimhan Praveenraj