Last month, three biologists were needed to carry 240 pounds (109 kilograms) of fish from the Detroit River in Michigan. Approximately 7 feet (2.1 meters) long “Monster sturgeon, “What was captured and released by the Alpena Fish and Wildlife Conservation Agency could be more than 100 years old. It’s certainly a very impressive catch, but is it the largest freshwater fish in the world?
The fish on the Detroit River is the lake sturgeon (Sturgeon), And considered one of the largest fish ever caught in the United States, larger fish are swimming in rivers around the world.by United States Geological Survey, The largest freshwater fish on earth is the Beluga sturgeon (Kaluga sturgeon), Black man between Europe and Asia, Azov, Caspian The sea, and the rivers that feed them.
Beluga sturgeons are up to 26 feet (8 m) long, about four times as long as king-sized mattresses, and weigh up to 2.2 tonnes (2,000 kg, or 2 m). Pan-European Action Plan for Sturgeon, Created by the World Sturgeon Conservation Society and the World Wildlife Fund.As they grow, beluga whales rise to the top of the food chain, with cockroach and cockroach fish, waterfowl, and even sticker, According to the International Union for Conservation of Nature (IUCN).
Beluga whales, like lake sturgeons, can live for over 100 years, giving them plenty of time to grow. “The longer you live, the more time you can eat,” Phaedra Doukakis, a fisheries policy analyst at the National Oceanic and Atmospheric Administration (NOAA), told Live Science.
Sturgeon has existed for over 250 million years and dinosaurBeluga is the largest of the 27 species of sturgeon and paddlefish living today.
Apart from its long lifespan, it is difficult to say exactly why beluga whales grow. Larger sturgeons are likely to have succeeded in breeding, as females can lay more eggs than smaller female fish. According to Leonardo Conziu, an associate professor of ecology at the University of Padua in Italy, its huge size can also help catch prey and survive predatory interactions.
However, today’s beluga may not reach more than 23 feet (7 m) in length. “I don’t think there is a beluga of that size anymore,” Kongiu told Live Science in an email. “This species is under great pressure from poaching, and probably all large animals have been captured.”
Congiu and his colleagues distributed in January 2021 genetically Beluga population diversity in the journal Diversity and distributionThey aim to reintroduce locally extinct fish into Italian rivers due to overfishing and dam construction.
Beluga sturgeon is designated as an endangered species. Endangered IUCN Red List, The most endangered category. Adult fish are prized for fish eggs, sold as caviar and worth more than $ 3,500 / pound. ($ 8,000 / kg), according to IUCN.
Doukakis, co-chair of the IUCN Sturgeon Expert Group, believes that beluga whales over 23 feet could be there, but there will be considerable bounties in their heads. “Old females who have achieved this species of length can carry caviar, which can be very expensive and very advantageous for poaching,” she said.
Sustainably farmed caviar is now available, but Dukakis says young individuals mature to maximum length, even with maximum protection for wild beluga. Explained that it will take a long time.
The title of the largest growing sturgeon today may actually belong to the white sturgeon (Sturgeon), The largest sturgeon in the United States In fact, people are more likely to see white sturgeons that are larger than the Beluga sturgeon.
At present, white sturgeon is not endangered and its population is stable. IUCNBut like almost all sturgeon species, they are threatened by the construction of dams. According to Doukakis, the dam prevents sturgeons from swimming upstream to reach spawning grounds and also changes the environmental conditions of the rivers they depend on.
Beluga and white sturgeon are called freshwater fish because they are born in freshwater and used for breeding, but they also live in seawater environments. Dukakis preferred to call it a freshwater-dependent fish to distinguish it from freshwater species.
What is the largest fish that lives only in freshwater? Mekong giant catfish (Pangasianodon gigas), Native to the Mekong River in Southeast Asia, holds the record. These catfish grew to 10 feet (3 m) in length and were previously captured at a weight of 646 lbs. (293kg), Live science Reported earlier. Like the beluga, these fish are considered endangered. IUCN, For dams and overfishing.
Initially published in Live Science.
What is the largest freshwater fish in the world?
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