Bowhead sharks can live more than 400 years, the period of puberty in females occurs at 156.
Kalaallisut, or malogolovy, shark (Somniosus microcephalus) is a species of polar sharks of the family amniotomy. In 1930-e years marine biologists have suggested that the age of these animals can reach 400 years – this conclusion was made on the growth of the body: about one centimeter per year. The length of adult individuals is 5-7 meters.
In the new study, the researchers tried to clarify the life expectancy of the Arctic sharks. It was used by the part of the spine sharks living in the waters of Greenland in the North Atlantic. The study of fibrous rings had been ineffective and the authors used radiocarbon analysis. The samples were made by the lens of the eyes of Greenland sharks caught in the region previously.
Radiocarbon analysis was aimed at identifying in the animal organism, carbon-14 is a radioactive nuclide, which is preserved in the aquatic ecosystem after two atomic bomb tests in the mid – 1950s and early 1960-ies. According to the hypothesis, higher and lower concentration of the isotope in interten tissues such as the lens pointed at the approximate age of the sharks.
The starting point was the conclusion that two of the examined sharks with a length of at least 2.2 meters were born after 1960-ies, one circa 1963. Based on this, researchers have constructed a growth curve to determine the age of other individuals, depending on the length of the body. Most of them age, according to scientists, at the time of death was about 392 years plus or minus 120 years. Pregnant sharks had an average body length of four meters at least 150 years.
According to the authors, this indicator of longevity can contribute, including low water temperatures, which inhabit the Arctic shark. Such conditions allow to slow down their growth and biochemical processes of the body. In addition, early studies have shown that the cold is able to activate anti-aging genes that stimulate protein folding for disposal molecules that damage DNA and better to fight infections.
Before the oldest vertebrates on the planet were considered the bowhead whale, the maximum registered age of which amounted to 211 years. In July, scientists from the National Institute of aging has made a rating of the long-livers of the animal world, the leader of which was a deep-sea sponge Monorhaphis Chini – today its estimated to be 11 thousand years.
