While the dream of most humans is to live more than a century, these five resilient species live more than 100 years, with their secrets hiding in uninhabited places.
The common characteristic of these methuselahs is that they live in remote places, away from humans. This probably explains their longevity, as there is very little – if any – interference from man in the environments they flourish in.
Some of these species are endangered due to poaching, but in recent decades measures are taken to stop these illegal activities.
There are also long-living species that are not animals or fish that live unperturbed in the depths of the ocean for centuries or millennia, untouched by the world above the sea.
Aldabra Giant tortoise (100-200 years)
The lineage of this giant creature goes back millions of years, proving its remarkable resilience to Earth’s big changes in those times. Their story is one of adaptation, survival and a profound influence on the island ecosystem they call home.
The males weigh up to 250 kilograms (550 pounds), they have fat feet and they are covered by a scaly carapace like a shield, which is brown or tan. Their necks are long so they can sustain high above the ground. This has allowed them to survive and reproduce in varied landscapes.
Today this long-living tortoise species lives on the Seychelles & Comoros Tropical Islands Bioregion of the same name. Once these huge creatures were found in several islands in the Indian Ocean and Madagascar, but they became extinct in those areas due to poaching and over-exploitation of their habitat.
Today, the atoll of Aldabra, an isolated terrain virtually untouched by human influence, is home to the world’s largest population of these gentle giants, estimated at around 152,000.
With their long nails they carve the ground and feed on grasses, leaves, woody plant stems and fruit as well as small invertebrates and carrion on occasion. They feed in the morning and rest in the sun for the rest of the day. When it’s hot, they may dip in pools or hide in the shade of trees. They are lonely creatures and congregate only during breeding season.
Females lay clutches of up to 25 eggs in nests dug 30 centimeters deep. After an eight-month incubation, they give birth to tiny hatchlings. The infants are very vulnerable and few of them survive in the wild.
Nevertheless, the Aldabra Giant tortoises are among the longest-living animals on Earth. Some individual Aldabra giant tortoises are thought to be over 200-years-old. Scientists attribute that to their slow metabolism.
Bowhead Whale (200+ years)
The bowhead whale is a large baleen whale with a body mass of up to 100 tons and a length of up to 20 meters, making it one of the largest animals on the planet. Females are slightly larger than males. This massive creature is named ‘bowhead’ because of its arched lower jaw that looks like an archer’s bow. The bowhead whale has a disproportionally large head which constitutes more than one-third of the entire length of the animal and lacks the dorsal fin, common in most whales.
The color of this giant long-living species is mostly black but much of its chin and lower jaw is white. A row of pigmented spots is also located on each side of the lower jaw. The bowhead whale is the longest-living mammal on the planet and can reach an impressive age of more than 200 years.
In 2016, there was a total of roughly 8,000 North Atlantic bowhead whales, mainly in the east Canada and western Greenland. However, the animal can be found in the circumpolar Arctic and sub-Arctic waters, both in northern Atlantic and Pacific waters.
Historically, native fishermen hunt the bowhead whale. A previous large commercial hunt decimated the populations. Currently in the North Atlantic, few bowhead whales are taken by Inuit in Canada and Greenland.
Greenland Shark (400+ years)
Greenland sharks live in freezing depths of the Arctic and North Atlantic oceans, making scientists suspect that they are one of the longest-living shark species. The age of other shark species can be estimated by counting growth bands on fin spines or on the shark’s vertebrae. Greenland sharks, however, have no fin spines and no hard tissues in their bodies.
The giant fish spends its entire life in deep, arctic waters and moves very slowly, growing equally slowly: less than one centimeter a year. One theory says that that they grow so slow because of their unique metabolism.
In 2016, however, scientists finally estimated the age of these freezing sea giants, which can grow longer than six meters (20 feet). They turned to carbon dating, which is usually reserved for long-dead organic matter. Greenland sharks are born with a special protein in their eyes that never deteriorates.
One study examined Greenland sharks that were caught in fishermen’s nets. The largest shark they found was a 5-meter female, between 272 and 512-years-old according to their estimates. Carbon dating can only provide estimates, not a definitive age. But even at the lower end of the estimates, a 272-year lifespan makes the Greenland shark the longest-lived vertebrate.
Long-living species have cancer-fighting powers. The Greenland shark’s genome in particular is twice as large as humanity’s and contains multiple copies of genes that play a role in DNA repair and tumor suppression.
Ocean quahog (500+ years)
Another slow pacer is the Ocean quahog, a rubbery little clam commonly found in clam chowder. Its scientific name is Arctica Islandica and it is actually the oldest mollusk species on Earth. Ocean quahogs are native to the North Atlantic, where fishermen only harvest mature specimens; at least 60 years or older. This long-living species dates back to the Jurassic period.
At first sight, an Ocean quahog is a fairly plain, quite large and rounded clam. Its shell is made up of two hinged parts called valves that protect the soft body parts inside. When fresh and alive, the clam is covered in a dark, skin-like layer called the periostracum, so it’s also known as a black or mahogany clam.
In 2006, an expedition from Bangor University in Wales found an especially large ocean quahog off the coast of Iceland. Using a powerful microscope, they counted the rings on the clam’s shell, which each correspond to a year of life. The clam turned out to be 507-years-old. That is far too many years inside a shell.
Clams like the ocean quahog live so long because they do so little. All day long they ingest sea water and filter out nutrients. This clam simply doesn’t age.
Glass Sponge (11,000 years)
The glass sponge belongs to the Euplectellidae family. This species of coral and sponge seems to stretch the definition of animal life making it one of the oldest animals on Earth. Their tissues contain glass-like structural particles, called spicules, that are made of silica, hence their name.
Most glass sponges live attached to hard surfaces and consume small bacteria and plankton that they filter from the surrounding water. Their intricate skeletons provide many other animals with a home.
Sponges are filter feeders that excrete exoskeletons made out of minerals absorbed from seawater. Glass sponges first evolved 650 million years ago, a time before the dinosaurs. For years scientists thought they were long extinct until an entire reef of glass sponges was found on a deep ocean floor in Canada in 1987.
A team of scientists managed to estimate the ages of these sponges. By studying the composition of the sponge’s silica layers and comparing it to historic ocean temperature data, they calculated that the glass sponge was roughly 11,000-years-old (with a margin of error of ± 3000 years).
The most famous glass sponge is a species of Euplectella, known as the “Venus flower basket,” which builds its skeleton in a way that entraps a certain species of crustacean inside for life.