How Greenland sharks live for hundreds of years without going blind

Greenland sharks, recognized as the most long-lived vertebrates on the planet, exhibit no signs of retinal degradation even after centuries of existence. This discovery is particularly astonishing given that some researchers hypothesized the creatures might be effectively blind due to their habitat in profoundly dark, deep waters.

Lily Fogg, affiliated with the University of Basel, Switzerland, alongside her team, carried out anatomical examinations of the eyes from eight deceased Greenland sharks (Somniosus microcephalus). Additionally, they sequenced the sharks’ DNA.

Resilient Retinas

Contrary to human eyes, which frequently undergo age-related deterioration, a study revealed that Greenland sharks maintain intact retinas well beyond a century. Over time, the human eye often succumbs to various ailments, including:

• cataracts
• macular degeneration
• glaucoma

However, the Greenland shark’s retinal integrity, even into extreme old age, suggests a remarkable adaptation to their deep-sea environment.

Peculiar Findings from Deep-Sea Studies

The research underlines the adaptive capability of Greenland sharks and presents an opportunity to comprehend the processes that thwart age-related retinal decline in these animals.

As Greenland sharks inhabit the cold waters of the Arctic and North Atlantic, they face unique environmental stressors. Research suggests that the cold and lack of light in their habitats might play a role in preserving their retinal health.

Deep-Sea Animal Vision

The remarkably intact vision of these creatures challenges current perceptions of deep-sea survival strategies. Most deep-sea organisms have evolved bioluminescence or heightened senses to navigate their dark surroundings.

Eye Retinas Survive Degeneration

The research team uncovered that certain retinal cells in Greenland sharks seem to stay healthy throughout their extraordinarily lengthy lifespans.

Comparative Biology

Drug development innovations for human ocular health have previously drawn from comparative biology. By analyzing how these sharks manage to dodge retinal aging, researchers hope to uncover better treatments methods for human eye conditions.

The study utilizes ancient vertebrate retinas’ resilience, highlighting the necessity of further exploring the genetic underpinnings of these age-defying mammals.