In 2006, a group of British scientists conducted a research cruise in Icelandic waters. When the large net laid down by the ship crossed the seabed, the creatures perched on the seabed were immediately taken away from the seabed. This web allowed scientists to harvest a batch of precious experimental samples, including a mollusk known to humans - the Arctic clam "Ming".
Arctic clam "Ming" specimen | Bangor University
Clams also have "rings"
Scientists saw "Ming" at first glance and did not find it special. This clam looks ordinary, 8.7 cm long, and seems to be no different from other large clams that can be played with in the palm of your hand. But when they counted the growth wheels on its shell, everyone was stunned.
Like trees, there is also a circle of "annual rings" on the clam shell, and for each year of growth, there is one more ring of annual rings. The growth wheel can be observed on both the inner and outer sides of the shell, as well as on the ligaments, but the outer side is susceptible to wear and tear, resulting in blurred lines, and the ligaments that connect the two shells are often considered the best place to calculate the growth wheel. In order to figure out the age of "Ming", the scientists decided to open it and use a microscope to observe the growth wheels on the ligaments. The answer was, 405 years old. Speculating that the year of its birth was during China's Ming Dynasty, scientists gave it such a romantic name.
The growth lines on the inside of the shell | Rob Witbaard
But this method of calculating age has strong limitations, because the age of "Ming" is really too big, and the growth wheels are superimposed in circles, while the clams themselves almost stop growing after reaching a certain age. More than 500 annual rings are squeezed on a surface of only a few millimeters, which causes some growth wheels to be positioned too close, or too flat, which can easily cause observation errors.
The "rings" of the Arctic clam shell are | Hans Hillewaert / Wikimedia Commons
In 2013, scientists decided to re-evaluate the age of Ming, this time using more advanced and sophisticated measurements such as carbon-14 dating. The new count rose to 507 years, a full century more than before. Scientists are confident in the accuracy of the results of this assessment, saying that the error will only be within 1-2 years.
That is to say, "Ming" was probably born as early as 1499. In this year, the Ming Dynasty of China reached its peak under the rule of Emperor Xiaozong of Ming, the Holy Roman Emperor Maximilian I recognized the independence of Switzerland, and the world-famous painting "Mona Lisa's Smile" has not yet been written. In 507 years, the world changed dramatically. Great empires rose and fell, the Industrial Revolution changed human society, two world wars claimed millions of lives, and "Ming" has always been silent in the quiet and dark seabed.
The Arctic clam that rushed ashore | nz_willowherb / Flickr
Clam's "Longevity Cheats"
The emergence of "Ming" brings more than just surprises.
When its news dominated the headlines, the voice of criticism and invective followed: "Kill the oldest animal in the world to calculate its age? There is nothing more ironic than that! ”
An Arctic round clam obtained in Strömstad, Sweden, | Karlafg / Wikimedia Commons
The researchers explained that due to the need for the preservation of biological samples, all clams are frozen at low temperatures shortly after being caught, and then transported to the laboratory for research, and the possibility of survival after freezing and transporting is already very low; and the 200 clams collected account for only a small part of the entire population.
Arctic clams (and other seafood) in Norwegian markets | Wolfmann / Wikimedia Commons
In terms of probability, the probability of the world's longest-lived animal is actually "very small", and the older clams are likely to still be lurking somewhere in the depths of the ocean.
A 2011 study showed that it is not uncommon for Arctic clams to be over 100 years old, and individuals over the age of 100 have been found in the Irish Sea, the North Sea and other waters. Given that the marine clams of the North Atlantic have always been a common ingredient in clam chowder, perhaps many people in the world have unknowingly eaten these hundreds of years old clams.
Clam soup | Jen / Wikimedia Commons
Why do Arctic clams live so long? Scientists have conducted a series of studies on this. Some people think that the reason is that their oxygen consumption is very low, the metabolism is very slow, so they have the super power of "freezing age"; others have proposed that the arctic clam's extremely high protein stability and the specificity of the cell turnover rate may also be the secret of its longevity.
Today, scientists are still looking for clues in the "Ming" growth wheel, trying to crack the "secret" of these longevity organisms anti-aging, and then bring inspiration to the research related to prolonging human life.
A record book of the marine environment
The scientific value of "Ming" does not stop there. In 2006, when the net was cast on the sea, scientists were expecting these clams to detect changes in the marine environment over the past thousand years.
As mentioned above, Arctic clams can easily grow to a hundred years old, and their growth wheel is like a miniature record, integrating information such as water temperature and food over time, so it can be used to deduce the climate and environmental changes in their growth. For example, by detecting various oxygen isotopes in the rings, scientists can determine the temperature of the seawater at the time of shell formation. Therefore, a clam is a record book of the marine environment.
These Arctic round clam shells will be a reference for us to speculate on the ancient climate| Hannes Grobe/AWI / Wikimedia Commons
Analysis of ming and other clams in the sample shows that changes in the atmospheric environment are driving changes in sea temperature and ocean currents since the beginning of the Industrial Revolution, and these important findings will help us better understand the subsequent effects of human-induced climate change. "There are many ways to map changes in terrestrial climates, but in the oceans, the data available to us is very limited. Arctic clams, because of their longevity properties, can effectively help us fill this gap and provide us with very accurate marine climate change data. The researchers said in an interview.
The Arctic round clam in the museum, this clam is likely to have a lifespan of more than a hundred years | Jennifer Boyer / Wikimedia Commons
Although the life of the "Ming" came to an abrupt end due to a scientific study, its appearance gave the world a reminder that there are many mysteries hidden in the oceans that have not yet been discovered by mankind.
Source: The article is authorized to be transferred from the species calendar, please contact [email protected] and CCTV for reprinting
berlika | author
Meng Xia | edit