Quick glance: the longest-lived animals

• Deep-sea black corals (Leiopathes spp.): 4,000+ years (colonial animals)
• Glass sponges (Hexactinellida, e.g., Monorhaphis chuni): several thousand years (some estimates suggest >10,000)
• Ocean quahog (Arctica islandica): 507 years verified individual
• Greenland shark (Somniosus microcephalus): likely 250–400+ years
• Bowhead whale (Balaena mysticetus): 200+ years
• Rougheye rockfish (Sebastes aleutianus): up to ~205 years; orange roughy (Hoplostethus atlanticus): 150–200+ years
• Giant tortoises (Galápagos, Aldabra, Seychelles): often 150+ years (some over 190)
• Red sea urchin (Mesocentrotus franciscanus): commonly 100–200+ years
• Hydra and Turritopsis dohrnii (“immortal jellyfish”): exhibit negligible aging or life-cycle reversal in lab conditions

Ocean quahog (Arctica islandica): the 500-year clam

One of the most famous individuals ever aged was a quahog nicknamed “Ming,” collected off Iceland and dated to 507 years. Scientists determine ages in these clams by counting growth lines in their shells and cross-checking with radiocarbon techniques—a field called sclerochronology.

Astounding fact: These clams are living environmental archives. Their annual shell layers record ocean temperature and chemistry, offering a centuries-long climate logbook. The trade-off for longevity is a slow pace of life: quahogs grow slowly, reproduce late, and are vulnerable to seabed dredging.

Greenland shark: a vertebrate that spans centuries

Greenland sharks drift through icy North Atlantic and Arctic waters at a deliberate pace—and seemingly through time. Radiocarbon dating of the proteins in their eye lenses suggests lifespans of at least 250 years, with some individuals likely over 400 years. They grow just millimeters per year and may not reach sexual maturity until around 150 years of age.

Astounding fact: Their eyes often host a parasitic copepod that clouds vision, yet the sharks rely on other senses in the deep and dark. Their extreme longevity likely reflects a slow metabolism in near-freezing waters, reduced predation, and a “live slow, age slow” life strategy.

Bowhead whale: the 200-year leviathan

Bowheads inhabit Arctic seas and hold the record among mammals for longevity. Some individuals have been estimated at over 200 years old—helped by the discovery of antique harpoon fragments embedded in recovered whales. Genetic studies hint at enhanced DNA repair and cell-cycle control mechanisms compared with other mammals.

Astounding fact: Bowheads have unusually thick blubber and baleen plates adapted to polar life. Their slow reproduction (calving intervals of several years) combines with long lives to make populations sensitive to overharvest but also to give them time to recover under strong protections.

Giant tortoises: island sages

Galápagos and Aldabra giant tortoises routinely exceed 100 years; some documented individuals are over 150, and one Seychelles giant tortoise known as Jonathan is over 190 years old. Their longevity is linked to slow metabolism, low predation on remote islands, and robust cellular maintenance.

Astounding fact: Giant tortoises exhibit “indeterminate growth” (they keep growing slowly after maturity) and can endure long periods without food or water—an energy-sparing lifestyle that pairs naturally with a long lifespan.

Rockfish and orange roughy: elders of the deep

Rougheye rockfish can surpass 200 years, and orange roughy commonly reach 150–200 years. Age is estimated by counting annual rings in ear bones (otoliths), much like tree rings. These fish grow slowly and mature late—traits that promote longevity but make them extremely vulnerable to overfishing.

Astounding fact: Some long-lived deep-sea fish gather to spawn at predictable sites, magnifying fisheries impacts. Their recovery from depletion can take decades because each “generation” spans such a long timeframe.

Black corals and glass sponges: animals older than civilization

Though they look plant-like, corals and sponges are animals. Certain deep-sea black corals (genus Leiopathes) have been radiocarbon-dated at over 4,000 years old. These are colonial animals; while individual polyps turn over, the colony persists for millennia.

Glass sponges can also be extraordinarily long-lived. Growth records preserved in their glassy spicules indicate lifespans of several thousand years in some species; in a few cases, spicule records suggest ages that may exceed 10,000 years. Estimates are conservative because directly aging the whole organism is challenging.

Astounding fact: Both corals and sponges archive ocean history in their skeletons, encoding information on currents, productivity, and even past volcanic eruptions and nuclear testing via radiocarbon “bomb pulse” signatures.

Red sea urchins: spiny masters of maintenance

On rocky Pacific coasts, red sea urchins routinely live to 100–200+ years. They show little decline in reproductive capacity with age—a hallmark of negligible senescence. Their tissues maintain protein quality through robust repair and turnover, a cellular housekeeping feat that keeps them reproductively fit for a century or more.

Hydra: the ageless polyp

In laboratories, tiny freshwater Hydra show no increase in mortality with age and can, in principle, live indefinitely under ideal conditions. Their bodies teem with stem cells that continuously renew tissues, and certain gene networks help prevent the usual cellular wear and tear seen in aging animals.

Astounding fact: When conditions are right, hydra can reproduce asexually by budding while maintaining youthful tissues—an elegant example of biological maintenance that inspires aging research.

Turritopsis dohrnii: the “immortal” jellyfish

This small jellyfish can reverse its life cycle. Under stress or injury, it can transform its adult body back into a juvenile polyp stage—effectively resetting its biological clock. While not invincible (predation and disease still kill most), its transdifferentiation trick makes it unique among known animals.

Astounding fact: The same cells that form one adult tissue can reprogram into another, a phenomenon that fascinates regenerative medicine.

Planarians, sturgeons, koi, and the lobster myth

Planarian flatworms possess a population of stem cells that can regenerate entire bodies. In the lab, clonal lines have been maintained for many years with no signs of aging, supported by active telomerase that preserves chromosome ends.

Sturgeons (e.g., lake sturgeon) and some carp (including koi) can surpass a century in favorable conditions. A famous koi named Hanako was reported to be 226 years old based on scale analysis; while debated, multi-decade to century-long lifespans for koi are well documented.

And lobsters? They produce telomerase throughout life and show some traits of negligible senescence, but they are not immortal. They eventually die from disease, predation, or the energetic cost of molting.

How do scientists measure such great ages?

• Growth rings: Annual bands in shells (clams), otoliths (fish), and corals act like tree rings.
• Radiocarbon dating: Natural and “bomb-pulse” radiocarbon in tissues (e.g., eye lens proteins of sharks) provides calendar ages.
• Sclerochronology: Chemical and structural analysis of hard parts (shells, skeletons, spicules) reconstructs age and environment.
• Mark–recapture and long-term observation: Especially for reptiles, birds, and mammals monitored over decades.

Each method has caveats. For example, colonial organisms blur the line between individual and colony age, and very slow-growing deep-sea species can be misaged if ring deposition isn’t truly annual. Cross-validation with multiple methods improves confidence.

What lets some animals live so long?

• Cold, stable environments: Low temperatures reduce metabolic rate and cellular damage, stretching lifespans (e.g., Arctic sharks, deep-sea corals).
• Slow life history: Delayed maturity, low reproduction rates, and long lifespans evolve together in low-predation, resource-limited habitats.
• Superior maintenance: Enhanced DNA repair, protein quality control, and antioxidant defenses keep cells functional for decades to centuries.
• Indeterminate growth and dormancy: Continuous slow growth or the ability to pause development (as in some invertebrates) helps conserve energy.
• Colony continuity or life-cycle reset: In corals, the colony persists even as parts turnover; in Turritopsis, adults can revert to juveniles.

Why longevity research matters

These organisms are living laboratories for aging science. From hydra stem-cell dynamics to bowhead DNA repair and sea-urchin maintenance, insights from nature inform human health research on resilience, regeneration, and age-related disease.

There’s also a conservation imperative. Long-lived species tend to reproduce slowly, making them highly vulnerable to overfishing, habitat disruption, and climate change. Protecting deep-sea corals, managing fisheries for century-old fish, and safeguarding tortoise habitats are essential if we want these timekeepers of the natural world to endure.