Secrets of the Greenland Shark’s Longevity Revealed in New Study

The Greenland shark, a slow-moving giant of the North Atlantic and Arctic Oceans, holds the record as the longest-lived vertebrate. One individual, estimated at nearly 400 years old, provides evidence that these deep-sea predators far outlive other long-lived animals, including giant tortoises and bowhead whales.

These sharks, reaching over six meters in length and weighing more than 1,400 kilograms, grow at a glacial pace—just about one centimeter per year. Despite their sluggish speed, they are top predators, feeding on a variety of marine life, including seals.

For decades, scientists have sought to understand the secret to the Greenland shark’s extreme lifespan. Now, a team of researchers, led by scientists from the University of Tokyo, has provided the first chromosome-level genome sequence for this ancient species.

Their findings, published in the journal bioRxiv, reveal genetic traits that contribute to its remarkable longevity, resistance to disease, and adaptations to the deep sea.

Large animals with long lifespans often have unique genetic adaptations. Previous studies on elephants found extra copies of the TP53 gene, which enhances cancer resistance. Similarly, certain rockfish species possess gene variations that strengthen immune responses. Yet, until now, no genome-wide research had been conducted on the Greenland shark.

The challenge lay in the sheer size of its genome and the technical difficulties of sequencing sharks. The team used high-fidelity long-read sequencing to assemble a 5.9-gigabase genome, one of the most complete shark genomes ever mapped. With 37,125 protein-coding genes identified, the data revealed a blueprint of genetic adaptations linked to longevity, deep-sea survival, and disease resistance.

Comparisons with other shark species showed that the Greenland shark has expanded families of genes associated with DNA repair, immune system function, and cellular stress resistance. Many of these genes play a crucial role in delaying aging and preventing diseases such as cancer.

“Our research suggests that the Greenland shark has unique genetic adaptations that contribute to its ability to live for centuries,” the study authors noted. “These findings help us understand not only the biology of these sharks but also aging in vertebrates.”

Among the key findings, researchers identified genes involved in NF-κB signaling, a crucial pathway in inflammation and cellular protection. These genes—TNF, TLR, and LRRFIP—were present in higher numbers in the Greenland shark compared to shorter-lived shark species. NF-κB plays an essential role in immune response, cell survival, and cancer suppression.

The study also highlighted genes with strong links to cancer resistance. FOXF2, known for regulating tumor microenvironments, showed signs of positive selection. Similarly, FSCN1, a gene associated with cell migration and tumor progression, exhibited unique modifications. Another gene, MAD2L1BP, plays a role in chromosome stability and DNA repair—both critical factors in maintaining genetic integrity over a long lifespan.

“These genetic insights offer clues to how Greenland sharks remain healthy for centuries,” the researchers stated. “Their immune and DNA repair systems seem to be finely tuned for long-term survival.”

The Greenland shark’s habitat, often thousands of meters deep, poses unique challenges, including extreme pressure, cold temperatures, and minimal light. Genetic analysis revealed a specialized variant of the rhodopsin (RHO) gene, which enables vision in dim-light environments. This adaptation allows the shark to navigate in near-total darkness, much like other deep-sea fish species.

Further analysis suggested that the shark’s genes related to cardiovascular function and metabolic efficiency may also contribute to its longevity. Living in cold waters likely slows metabolic processes, reducing cellular wear and tear over time.

Despite their long lifespans, Greenland sharks face increasing threats from commercial fishing bycatch and climate change. These sharks take an estimated 150 years to reach maturity, making their populations highly vulnerable to overfishing. In 2019, the species was listed as vulnerable on the IUCN Red List, signaling the need for stronger conservation measures.

Scientists hope that further genomic research can aid in conservation efforts by identifying genetic markers that track population health and diversity. The newly sequenced genome provides a foundation for studying the species’ evolutionary history and how it may adapt to changing ocean conditions.

“The Greenland shark is a living time capsule, offering us an unparalleled opportunity to study aging and deep-sea adaptation,” the researchers concluded. “By understanding its biology, we may unlock new insights into longevity and disease resistance in other animals, including humans.”

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