Native to China’s Yangtze River, these fish grew seven metres in length, but haven’t been spotted since 2003.

The Chinese paddlefish and its close relatives have been around for at least 200 million years. The species, reaching up to seven metres in length, survived unimaginable changes and upheavals, such as the mass extinction that killed the dinosaurs and marine reptiles like plesiosaurs that it swam alongside. In its time, flowering plants evolved, and came to populate the shores of its ancestral home, the Yangtze River, in modern-day China.

Much later, bamboo came on the scene, and well after that, giant pandas. In the last few thousand years, a blink in evolutionary time, the land filled with people, and China became the most populous country on Earth. In the muddy waters of the Yangtze, the paddlefish lived as it had for eons, using its special sword-like snout to sense electrical activity to find prey, such as crustaceans and fish.

But there’s one phenomenon this ancient species, sometimes called the “panda of the Yangtze,” could not survive—humans. A new paper published in the concludes that the species has gone extinct, mainly due to overfishing and dam construction.

It’s “a reprehensible and an irreparable loss,” says study leader Qiwei Wei of the Chinese Academy of Fishery Sciences, who’s been looking for the animal for decades.

Chinese paddlefish () had a long sword-like rostrum, a snout-like structure packed with cells to detect electrical activity in prey animals such as crustaceans. They ranged over long distances throughout the expansive reaches of the Yangtze River basin, and even making their way into the East China Sea.
PHOTOGRAPH BY FLHC1, ALAMY

“It’s very sad,” adds Zeb Hogan, a fish biologist at the University of Nevada, Reno, and a National Geographic Explorer who wasn’t involved in the study. “It’s the definitive loss of a very unique and extraordinary animal, with no hope of recovery.”

Hogan says the paddlefish’s extinction should serve as a wake-up call to protect other freshwater species. Large fish, in which he specializes, are especially at risk: Most of the biggest freshwater animals are threatened with extinction, he says.

“This is the first of these very large freshwater fish to go and many are at risk—the concern is that more will go extinct, but the hope is that we can reverse their decline before it’s too late,” Hogan says.

Long goodbye

The species gradually declined over the last century thanks to overfishing; in the 1970s, 22.7 tonnes of paddlefish were harvested per year on average.

But what really did it in, the scientists conclude, were dams—specifically the Gezhouba Dam, built on the main stem of the Yangtze, a little over a thousand miles from the sea. This dam, which was constructed without a fish ladder or bypass, cut off the paddlefish from their only spawning grounds upstream, which had only been discovered in the late 1970s.

Populations of the fish continued to dwindle after the 1981 dam construction, but nobody had yet figured out how dire the situation was, says Ivan Jaric, a co-author and biologist at Czechia’s Institute of Hydrobiology and the University of South Bohemia. As is often the case, there can be a significant lag between major disturbances and their impact. The researchers estimate the fish had become functionally extinct by 1993, meaning there were not enough fish to meaningfully reproduce.

) was seen alive in 2003, and they’ve been declared extinct. Due to their rarity, and untimely demise, there are very few photos of the species.
PHOTOGRAPH BY QIWEI WEI

    Sourse: www.nationalgeographic.com.au

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