Freshwater fish - Artensterben

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)

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)

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.

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)

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

At a body length of around 9.5 centimeters, the Abrau sprat is a relatively small fish. (© Лев Семёнович (Симонович) Берг (2 (14) марта 1876 — 24 декабря 1950), Public domain, via Wikimedia Commons)

3. September 2024 Doreen Fräßdorf

Russia: Believed-to-be-extinct Abrau Sprat Rediscovered

In October 2019, researchers collected nine small fish during an expedition from Lake Abrau in the Krasnodar region of western Russia. Recent DNA analyses have confirmed that the captured fish are indeed the endemic Abrau sprat (Clupeonella abrau), a species that had not been recorded since 2008. Challenges for the

Haplochromis vonlinnei holotyp Buntbarsch Victoriasee

The brownish-gray cichlid Haplochromis vonlinnei reached a length of nearly 16 centimeters. Its snout was relatively pointed and its teeth strongly curved. It is assumed that the species was a specialized piscivore, as remains of smaller cichlid species were found in the intestines of collected specimens. (© Eelco Kruidenier, CC BY 3.0, via Wikimedia Commons)

11. March 2024 Doreen Fräßdorf

Haplochromis vonlinnei (Cichlid)

One of 500 Furu — Haplochromis vonlinnei Haplochromis vonlinnei is a probably extinct cichlid species from Lake Victoria in East Africa. The original scientific description of the species was published in 2008 by Dutch ichthyologist Martien J. P. Van Oijen based on five specimens caught between 1978 and 1980 in

Drawing of a Chinese paddlefish from 1868. The frontal portion made up around one-third of the fish's total length. Chinese paddlefish reached lengths of more than three meters and weights of up to 300 kilograms. (© Muséum d'histoire Naturelle, Public domain, via Wikimedia Commons)

8. August 2021 Doreen Fräßdorf

Chinese Paddlefish

An ancient swimming fossil in the Yangtze River—the Chinese paddlefish The Chinese paddlefish and its relatives were already swimming through Earth’s waters more than 100 million years ago. This freshwater predator, said to have reached lengths of seven meters and weights of several thousand pounds, survived the mass extinction 66

There are hardly any images of Acanthobrama hulensis. The photo shows the fish Acanthobrama telavivensis from Israel, which belongs to the same genus. (© MERRYcristhmas, CC BY-SA 4.0, via Wikimedia Commons)

18. July 2018 Doreen Fräßdorf

Hula bream

Drainage of lake and wetland led to extinction of fauna The wetlands surrounding the 20 square kilometer Hula Lake (also known as Hula Lake, Chula Lake) in Israel were artificially drained in the 1950s to create agricultural land. Within a few years, the endemic fauna of the lake—including the Hula

Kilch and deepwater char (one animal at bottom left) by Emil Walter from his book Our Freshwater Fish from 1913. (© Walter, Emil, Public domain, via Wikimedia Commons)

10. March 2018 Doreen Fräßdorf

Lake Constance whitefish

Lake Constance whitefish inhabited the lake’s deep zones The freshwater fish Lake Constance whitefish was once native to the deep parts of Lake Constance. The olive-green or brown fish could reach a length of around 29 centimetres and weighed about 125 grams. Initially, the physician and naturalist Johann Friedrich Gmelin