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The Immortal Jellyfish

Let’s start with the oldest-living animal of all, and one of the strangest in the entire animal kingdom: Turritopsis nutricula, otherwise known as the immortal jellyfish. You might think that this animal’s common name is poetic, that perhaps it lives for a few hundred years, impressing generations of scientists–but you’d be wrong. Its name is literal: Turritopsis nutricula is biologically immortal. The immortal jellyfish can theoretically live forever, thanks to a process that is believed to be unique, called transdifferentiation. It has the ability, at any stage in its life, to completely transform back into a polyp, its earliest stage of life. You can imagine it like the mythical phoenix, an immortal bird which is repeatedly reborn as a chick. The immortal jellyfish doesn’t die; it merely regenerates its cells in a younger stage, then ages naturally again. That doesn’t mean all Turritopsis nutricula are immortal; the species is a small invertebrate in the ocean, and is susceptible to all of the nasty things that can befall such creatures, whether that’s being eaten or succumbing to disease. But it is biologically capable of immortality. The New York Times Magazine ran a great article about the immortal jellyfish last year–highly recommended reading.

Bowhead Whale

The bowhead whale, a baleen whale native to the Arctic Ocean, was originally assumed to be a member of the right whale genus. Turns out it’s distinct, though rare, at fewer than 25,000 strong. It is a massive whale, reaching lengths of nearly 70 feet, with a huge, bony head it uses to smash through the arctic ice-sheets in order to breathe, and the largest baleen “teeth” (really, more like a sieve used to strain out small creatures for food) of any whale. The bowhead whale is also currently believed to be the world’s longest-living mammal. Most similar whales (meaning cold-water baleen whales) live for a long time, around 60 or 70 years, but scientists were shocked when, in the 1990s, bowhead whales were discovered with scars from 19th-century weapons made of ivory and jade. Advanced dating techniques, including amino acid dating, found that some bowhead whales reach ages of up to 200 years–and the oldest known bowhead whale was 211 years old.


The bizarre-looking, highly phallic geoduck is a bivalve clam native to the coastal waters of the Pacific Northwest, especially Puget Sound in Washington state. The name (pronounced “gooey-duck”) is derived from an American Indian phrase meaning “dig deep”–fitting, because these huge clams live deep in the mud flats of their coast. But you’ll want to dig deep, because geoduck is a delicacy, with a mild brininess and crunchy texture that has in recent decades become very trendy, especially in Asia. The geoduck is one of the largest clam species in the world, reaching up to four feet in length (its siphon makes up the majority of this length), and it’s also one of the oldest, routinely living for more than a hundred years. The oldest known geoduck to be scientifically dated was a whopping 168 years old.

Aldabra Giant Tortoise

Large tortoises are often very long-lived; individual Galapagos tortoises, Greek tortoises, and radiated tortoises have all been known to live longer than 150 years. But by far the longest-lived tortoise in recorded history is a fellow named Adwaita, a male Aldabra giant tortoise, who lived to be a ridiculous 255 years old. Adwaita, whose name means “one and only” in Sanskrit, first appeared in history as a pet of General Robert Clive, a British general who captured four such tortoises from the Aldabra Atoll, a chain of small coral reef islands in the Seychelles, off the coast of Madagascar. Adwaita passed away in 2006, in a zoo in India. Robert Clive, on the other hand, died in November of 1774. The Aldabra giant tortoise is massive, one of the biggest in the world. Males weigh, on average, 550 pounds. Bizarrely, they are sometimes kept as pets, even though they are huge and powerful and can destroy most enclosures. Also they’ll outlive you, and your children. And your grandchildren.


The tuatara is a reptile native to New Zealand. You might look at it and think it’s a lizard like so many others, but in fact, it is a very unusual branch of the reptile tree and is not closely related to any extant lizards or snakes. In fact, it’s not a lizard at all; it’s a very primitive reptile that shares almost as many traits with birds as it does with lizards, which makes it of great interest to evolutionary biologists. The tuatara is unusual for lots of reasons; it has a single-chambered lung, the most primitive heart of any reptile, its teeth are not teeth but rather jagged outcroppings of its jawbone, its spine resembles that of a fish more than any other reptile, and, oh, wait, it has three eyes. Yes. Three eyes. And its lifespan is just as weird; it reaches sexual maturity extremely late, at between 20 and 30 years, and doesn’t even stop growing until its 35th year. That means the tuatara is also extremely long-lived, frequently breaking the century mark. A tuatara named Henry became a father at age 111, back in 2009, and some experts believe the tuatara could reach 200 years in captivity.

American Lobster

The American lobster, native to the cold waters of the northwestern Atlantic from Labrador to North Carolina, is one of the biggest crustaceans in the world, reaching weights of 44 pounds and lengths of up to two feet. It’s a delicacy throughout North America, but it’s also capable of living well past a century. One lobster, captured off the coast of Newfoundland in 2008 and sold to Manhattan’s City Crab and Seafood restaurant (for a whopping $100), turned out to be an estimated 140 years old. The owner of the restaurant named the lobster George, and insisted that George was never intended to be sold or eaten; he was kept in a tank in the restaurant and served as an attraction thanks to his large size. Eventually, thanks to efforts by PETA, George was released into the waters off Kennebunkport, Maine, chosen because fishing is prohibited there.