The polar shark and the secret to its longevity

The polar shark is the true record-holder of the Arctic depths – a creature that seems to play with the passage of time. This mysterious inhabitant of the cold waters of the Arctic Ocean can live up to 400 years, making it one of the most long-lived vertebrates on Earth. Researchers, fascinated by its unusual nature, are trying to work out the mystery of this longevity. Can this peaceful giant offer clues on how to extend human life?

Polar shark – the longest-lived vertebrate on Earth

The polar shark, also known as the Greenland shark(Somniosus microcephalus), is an inhabitant of the frigid waters of the Arctic Ocean and the North Atlantic. It can be encountered at depths of 400 to as much as 2,200 meters, where conditions are hostile to most forms of life. This predator grows to an impressive size – adults can measure up to 7 meters in length and weigh over a ton, placing it among the world’s largest sharks. However, it moves at an almost lazy pace – its average speed is just 2 km/h. Living in such an extreme environment, where temperatures range from -1.8°C to 7.5°C and access to oxygen is limited, requires unique adaptations.

Scientists estimate the age of these sharks by analyzing proteins in the lenses of their eyes, which accumulate there throughout their lives (like layers in a tree trunk). The results are astonishing – some individuals can be from 272 to as old as 500 years! This record longevity has attracted the attention of researchers, who are trying to unravel the mystery: how does the polar shark organism cope with such harsh conditions for centuries?

Why do polar sharks live so long?

The secret to the Greenland shark’s longevity lies in its genome – a biological treasure trove of some 6.5 billion base pairs. This is almost twice as much as that of humans, who have only 3 billion. Interestingly, more than 70 percent of the shark’s DNA consists of transposons, or so-called jumping genes – mobile fragments that in other organisms often cause mutations and destabilize the genetic code. In his, on the other hand, these elements are under tight control, a fact that astonishes scientists.

Researchers suspect that the key lies in the unique structure of the genome, which evolved in response to living in cold waters. Where metabolism slows to a minimum, the shark seems to manage energy in a way not seen in other species. This slow pace of life, coupled with the unique organization of DNA, avoids genetic chaos and lasts for centuries.

Genetic stability: the key to eternal life?

The Greenland shark stands out for something else – the remarkable stability of its DNA, which seems to be a shield against the passage of time. Genetic analyses of individuals that have survived for hundreds of years reveal surprisingly few changes in their genetic sequences. In this shark, unlike in humans or other animals, where mutations accumulate with age, leading to aging and disease, these processes hardly occur. Scientists point out that advanced DNA repair mechanisms here work like a precision watchmaker, repairing any damage with remarkable efficiency.

In the cold depths, under immense pressure, where every cell must function sparingly, the polar shark retains the integrity of its genetic code. This trait makes it living proof that nature has found a way to cheat old age – a way that is still beyond the reach of most organisms on Earth.

In addition, the shark grows at a rate of just 1 cm per year, showing how sparingly it manages its biological resources. These traits allow it to survive in environments of tremendous pressure and low temperatures, where other species would quickly succumb. The genetic stability of the polar shark is a kind of wall that protects it from the passage of time – something that for us still remains a distant dream.

Slow development and unique lifestyle

The Greenland shark amazes not only with its lifespan, but also with the speed at which it develops. It reaches sexual maturity only after about 150 years. Its growth and metabolism are so slow that biological processes span decades, minimizing energy consumption and cellular damage. It feeds mainly on carrion, although it does not shy away from hunting fish or even marine mammals, making it easier to survive in the deep, where food is hard to come by.

Living in waters near 0°C and under tremendous pressure requires it to be extremely resilient. The polar shark owes it to its unique adaptations – from its slow metabolism to its ability to function in conditions that would be lethal to most organisms. It is this unhurried rhythm of life that allows it to last for centuries.

Inspiration for science: what can we learn from the shark?

The polar shark is more than a natural curiosity – it’s a natural laboratory that can teach us how to fight aging. The DNA repair mechanisms that protect its genome for hundreds of years raise hopes of discovering new ways to prevent diseases of aging, such as cancer and Alzheimer’s disease. The ability to control transposons and minimize mutations are features that scientists would like to transfer to human biology.

Although the shark lives in a world of cold depths far removed from our own, its adaptations carry universal lessons. Research into the specific proteins responsible for DNA repair could result in future medical breakthroughs. The Greenland shark, with its slow rhythm of life and genetic harmony, reminds us that nature still hides the answers to questions humanity has been asking for centuries. Will we one day use its secrets to cheat time?