The 11 Longest-Lived Animals Can you outlive a salamander? We'd like to see you try
We humans like to pride
ourselves on our long (and getting longer all the time) life spans but the
surprising fact is that, in terms of longevity, Homo sapiens has nothing on
other members of the animal kingdom, including sharks, whales, and even
salamanders and clams. In this article, discover the 11 longest-lived members
of various animal families, in order of increasing life expectancy.
Longest-Lived Insect - The Queen Termite (50 Years)Queen Termite
One normally thinks of
insects as living only a few days, or at most a few weeks, but if you're a
particularly important bug all the rules go out the window. Whatever the
species, a colony of termites is ruled by a king and queen; after being
inseminated by the male, the queen slowly ramps up her production of eggs,
starting with a mere couple of dozen and and eventually attaining levels of close
to 25,000 per day (of course, not all of these eggs mature, or else we'd all be
knee-deep in termites!) Unmolested by predators, termite queens have been known
to reach 50 years of age, and the kings (who spend pretty much their entire
lives holed up in the nuptial chamber with their prolific mates) are comparably
long-lived. As to those plain, ordinary, wood-eating termites who constitute
the bulk of the colony, they only live for one or two years, max; such is the
fate of the common slave.
Longest-Lived Fish - The Koi (50 Years)Koi fish
In the wild, fish
rarely live for more than a few years and even a well-cared-for goldfish will
be lucky to reach the decade mark. But few fish in the world are more tenderly
indulged than koi, a variety of the domestic carp that populates the "koi
ponds" popular in Japan and other parts of the world, including the U.S.
Like their carp cousins, koi can withstand a wide variety of environmental
conditions, though (especially considering their bright colors, which are
constantly being tinkered with by humans) they're not especially well-equipped
to defend themselves against predators. Some koi individuals have been reputed
to live for over 200 years, but the most widely accepted estimate among
scientists is 50 years, which is still a lot longer than your average fish-tank
denizen.
Longest-Lived Bird - The Macaw (100 Years)Macaw blue parrot
In many ways, macaws
are unnervingly similar to suburban Americans of the 1950's: these colorful
parrot relatives mate for life; the females incubate the eggs (and care for the
young) while the males forage for food; and they have human-life like spans,
surviving for up for up to 60 years in the wild and 100 years in captivity.
(Ironically, even though macaws have unusually long life spans, many species
are endangered, a combination of their desirability as pets and the devastation
of their rainforest habitats.) The longevity of macaws, parrots, and other
members of the Psittacidae family raises an interesting question: since birds
evolved from dinosaurs, and since we know that many dinosaurs were as small and
colorfully feathered, might some of the pint-sized representatives of this
ancient reptile family have attained century-long lifespans?
Longest-Lived Amphibian - The Cave Salamander (100 Years)Cave Salamander
If you were asked to
identify an animal that regularly hits the century mark, the blind salamander,
Proteus anguinus, would probably be close to last on your list: how can a
fragile, eyeless, cave-dwelling, six-inch-long amphibian possibly survive in
the wild for more than a couple of weeks? Naturalists attribute P. anguinus'
longevity to its unusually sluggish metabolism—this salamander takes 15 years
to mature, mates and lays its eggs only every 12 or so years, and barely even
moves except when seeking out food (and it's not like it requires all that much
food to begin with). What's more, the dank caves of southern Europe where this
salamander lives are virtually devoid of predators, allowing P. anguinus to
exceed 100 years in the wild. (For the record, the next longest-lived
amphibian, the Japanese giant salamander, only rarely passes the half-century
mark.)
Longest-Lived Primates - Human Beings (100 Years)An elderly Somali woman
Human beings so
regularly hit the century mark—there are about 500,000 100-year-olds in the
world at any given time—that it's easy to lose sight of what an astonishing
advance this represents. Tens of thousands of years ago, a lucky Homo sapiens
would have been described as "elderly" if she lived into her twenties
or thirties, and until the 18th century or so, average life expectancy rarely
exceeded 50 years. (The main culprits were high infant mortality and
susceptibility to fatal diseases; the fact is that at any stage of human history,
if you somehow managed to survive your early childhood and teens, your odds of
making it to 50, 60 or even 70 were much brighter.) To what can we attribute
this stunning increase in longevity? Well, in a word, civilization—especially
sanitation, medicine, nutrition, and cooperation (during the Ice Age, a human
tribe might have left its elderly to starve in the cold; today, we make special
efforts to care for our octogenarians and nonagenarians.)
Longest-Lived Mammal - The Bowhead Whale (200 Years)Bowhead whale
As a general rule,
larger mammals tend to have comparably longer life spans, but even by this
standard, the bowhead whale is an outlier: adults of this hundred-ton cetacean
regularly exceed the 200-year mark. Recently, an analysis of the Balaena
mysticetus genome shed some light on this mystery: it turns out that the
bowhead whale possesses unique genes that aid in DNA repair and resistance to
mutations (and therefore cancer). Since B. mysticetus lives in Arctic and
sub-Arctic waters, its relatively sluggish metabolism may also have something
to do with its longevity. Today, there are about 25,000 bowhead whales living
in the northern hemisphere, a healthy rebound in population since 1966, when serious
international efforts were made to deter whalers.
Longest-Lived Reptile - The Giant Tortoise (300 Years)Giant tortoise
The giant tortoises of
the Galapagos Islands and the Seychelles are classic examples of "insular
gigantism"—the tendency of animals confined to island habitats, unmolested
by predators, to grow to unusually large sizes. And these turtles have lifespans
that perfectly match their 500- to 1,000-pound weights: giant tortoises in
captivity have been known to live longer than 200 years, and there's every
reason to believe that testudines in the wild regularly hit the 300-year mark.
As with some of the other animals on this list, the reasons for the giant
tortoise's longevity are self-evident: these reptiles move extremely slowly,
their basal metabolisms are set at an extremely low level, and their life
stages tend to be comparably stretched out (for example, the Aldabra giant
tortoise takes 30 years to attain sexual maturity, about double the time of a
human being).
Longest-Lived Shark - The Greenland Shark (400 Years)Greenland shark
If there were any
justice in the world, the Greenland shark (Squalus microcephalus) would be
every bit as well-known as the great white: it's just as big (some adults
exceed 2,000 pounds) and much more exotic, given its northern Arctic habitat.
You can even make the case that the Greenland shark is just as dangerous as the
star of Jaws, but in a different way: whereas a hungry great white shark will
bite you in half, the flesh of S. microcephalus is loaded with trimethylamine
N-oxide, a chemical that makes its meat poisonous to humans. All that said,
though, the most notable thing about the Greenland shark is its 400-year
lifespan, which can be attributed to its sub-freezing environment, its
relatively low metabolism, and the protection afforded by the methylated compounds
in its muscles. Astonishingly, this shark doesn't even reach sexual maturity
until it's well past the 100-year mark, a stage when most other vertebrates are
not only sexually inactive but long since dead.
Longest-Lived Mollusk - The Ocean Quahog (500 Years)Ocean quahog
A 500-year-old mollusk
sounds like the setup for a joke: given that most clams are virtually immobile,
how can you tell if the one you're holding is living or dead? There are, however,
scientists who investigate this kind of thing for a living, and they have
determined that the ocean quahog, Arctica islandica, can literally survive for
centuries, as demonstrated by one individual that passed the 500-year mark (you
can determine the age of a mollusk by counting the growth rings in its shell).
Ironically, the ocean quahog is also a popular food in some parts of the world,
meaning that most individuals never get to celebrate their quincentennials.
(Biologists have yet to figure out why A. islandica is so long-lived; one clue
may be its relatively stable antioxidant levels, which prevent the cell damage
responsible for most signs of aging in animals.)
Longest-Lived Microscopic Organisms - Endoliths (10,000 Years)Endolith lifeform found inside an Antarctic rock
Determining the
lifespan of a microscopic organism is a tricky matter: in a sense, all bacteria
are immortal, since they propagate their genetic information by constantly dividing
(rather than, like most higher animals, having sex and dropping dead). The term
"endoliths" refers to bacteria, fungi, amoebas or algae that live
deep underground in the clefts of rocks; studies have shown that the
individuals of some of these colonies only undergo cell division once every
hundred years, endowing them with lifespans in the 10,000-year range.
(Technically, this is different from the ability of some microorganisms to
revive from stasis or deep-freeze after tens of thousands of years; in a
meaningful sense, these endoliths are continuously "alive," albeit
not very active.) Perhaps most importantly, endoliths are autotrophic, meaning
that they fuel their metabolism not with oxygen or sunlight, but with inorganic
chemicals, which are virtually inexhaustible in their underground habitats.
Longest-Lived Invertebrate - Turritopsis dohrnii (Potentially Immortal)Turritopsis dohrnii
There's no really good
way to determine how old your average jellyfish is: these invertebrates are so
fragile that they don't lend themselves well to intensive analysis in
laboratories. However, no list of the longest-lived animals would be complete
without a mention of Turritopsis dohrnii, a jellyfish that has the ability to
revert back to its juvenile polyp stage after reaching sexual maturity, thus
making it potentially immortal. However, it's pretty much inconceivable that
any T. dohrnii individual has literally managed to survive for millions of
years; just because you're biologically "immortal" doesn't mean you
can't be eaten by other animals or succumb to drastic changes in your
environment. Ironically, too, it's nearly impossible to cultivate T. dohrnii in
captivity, a feat that so far has been accomplished by only a single scientist
working in Japan.
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