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The coelacanth can live for a century. That’s not great news

The coelacanth can live for a century.  That’s not great news

They are African coelacanths Very old. Fossil evidence created their genesis about 400 million years ago, and scientists thought it was extinct until 1938, when the museum’s curator Marjorie Courtenay-Latimer he noticed a live in a fishing net.

It was found on the southeast coast of Africa, zelakantoak he lives a long time, too — scientists suspect About 50 years. But to prove that long life has been hard. (Celestials are endangered and accustomed to deep water, so scientists cannot put babies in a tank and start the timer.) Now, a French research team studying scales with polarized light has determined that they can surely live much longer. . “We were shocked,” says marine ecologist Bruno Ernande, who led the study. He says it has “lasted about a century.”

His team at the French Institute for the Exploitation of the Sea or IFREMER have found that individuals can live to be almost 100 years old but also have periods of pregnancy of at least five years, and may not be sexually mature until they are at least adults. 40. Results were published in on Thursday Current Biology. This slow-moving life highlights the importance of conservation efforts for this rare species, which is in danger of becoming “endangered”. IUCN red list. There are only about 1,000 in the wild, and long pregnancies and late maturity are bad news for the population to gain strength for its attempts at humans. “It’s even more dangerous than we thought,” says Ernand.

“It will have dire consequences,” agrees Daniel Columbiay, an ichthyologist at the University of British Columbia, who was not involved in the research. Pauly is the founder of FishBase, a database of biological and ecological information on ten thousand species. If a fish needs several decades to spawn, then killing it eliminates its ability to form a population. “Fish that need 50 years to reach maturity, more than 10 years, are five times more likely to have problems,” he says.

The coelacanths are thick scales that are two inches long, and for decades ichthyologists have been debating how to read these scales to get signs of age. In the 1970s, researchers identified small calcified structures on top of them. The rings were depicted as age marks, like tree rings. They did not agree, however, on how to count: Some believed that each mark represented a year; others believed that seasonal upheavals produced two rings a year. At the time, the best invention had a life expectancy of about 22 years. The conclusion was that a 6-meter, 200-pound coelacanth, which was 17 years old, said they were growing very fast: “They would grow as fast as tuna, that’s crazy,” says Pauly.

It is wonderful because they are animals with slow metabolisms, which should indicate slow growth. The hemoglobin of coelacanths is adapted to this slow metabolism, which means that they cannot take in enough oxygen to help a fast-growing fish. Some say that small gills are evidence of oxygen limitations. They also live very passive lifestyles, resting in caves all day and slowly crossing them. the sunset zone of the ocean, down to 650 feet and below, when they plan to move. “Greatly, the biological traits pointed to a slow-moving fish,” says Ernand.

In addition, scientists who have monitored the life of individual coelacanths have learned that 20 years is very low. In the 1980s, researchers he began sending submarines and remote vehicles to the cave, which housed between 300 and 400 zealots. They returned to this place more than 20 years ago. At each visit, individuals were known for the characteristics of the white marks. Only about three or four fish in this group would die and a new number would be born each year. This observation provided striking evidence that coelacanths have a long life, more than 100 years, that research says.

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