From animals that never seem to age to those
which can survive for years without food or water, here are 6 creatures that can live
forever. Number 6 Ocean Quahog
This edible clam species is native to the North Atlantic Ocean and renowned for its
longevity. After about 25 years, a period in which the
clam grows and reaches sexual maturity, scientists have found that its antioxidant enzymes maintained
stable level for more than 150 years. In many animal cells, the molecules that contain
oxygen react with the cell membranes, thus damaging parts of the cell. However, the membranes from the cells of ocean
quahogs are unusually resistant to this type of damage, which means that these creatures
age at a negligible rate. An ocean quahog was discovered by British
researchers off the coast of Iceland, in 2006. The clam died when they opened its shell,
in order to examine it. At the time, the researchers weren’t aware
of the clam’s age, which carbon dating would later place at 507 years old. The discovery received a great deal of media
attention and journalists from the Sunday Times dubbed the clam Ming, as it was born
during the Ming dynasty, towards the end of the 1400s. The researchers later named it Hafrun, which
roughly translates as ‘mystery of the ocean’. There’s no way to tell how long the clam
would have lived for if undisturbed from its natural habitat. Some have suggested that Ming might have been
a rare example of biological immortality. Number 5 Nematodes
Nematodes are the roundworms which account for about 80 per cent of all individual animals
on our planet. They’re present in every part of the Earth’s
lithosphere, including desserts, mountains and oceanic trenches. They’re also found as parasites in the bodies
of many vertebrates, including, in some cases, humans. According to nematologist Nathan Cobb ‘If
all the matter in the universe except the nematodes were swept away, our world would
still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we
should find its mountains, hills, vales, rivers and oceans represented by a film of nematodes’. Such is the ubiquity of nematodes on Earth. Another incredible attribute is their ability
of surviving in stasis for an extended period of time. In July 2018, Russian scientists collaborated
with researchers from Princeton University, to analyze around 300 prehistoric worms recovered
from Russia’s Sakha Republic, above the Arctic Circle. The nematodes were found in permafrost and
two of them began to move and eat after being thawed. One was believed to be about 32,000 years
old, the other approximately 41,700 years old. This makes them the oldest living multicellular
animals on Earth. Number 4 Lobsters
Research suggests that lobsters don’t stop growing, weaken or lose fertility with age. They grow through a process called ‘moulting’,
during which the lobster sheds its hard exoskeleton prior to growing a new one around a bigger
body. This process repeats itself with greater frequency
when the lobster is young and then once every two or three years after it passes a certain
age. Lobsters also retain their regenerative abilities,
which enable them to regrow lost limbs, into their advanced adulthood. It’s theorized that the reason these blue-blooded
creatures are often cited in the discussion of biological immortality has to do with an
enzyme called ‘telomerase’. The chromosomes in animal cells have long
repetitive sequences of DNA at their tips, which are called telomeres. As the cell divides and the chromosome is
replicated, the telomeres become shorter, in turn reducing lifespan. Telomerase is an enzyme that repairs these
chromosome tips and it’s expressed in most vertebrates only during embryonic stages. Lobsters, on the other hand, express telomerase
in most of their bodies as adults, an aspect which has been associated with their longevity. Number 3 Planarian Flatworms
These creatures are common to many parts of the world, living in both saltwater and freshwater
rivers and ponds. Planarian flatworms have the reputation of
being ‘immortal under the edge of a knife’. That’s because these extraordinary creatures
can be cut into pieces and each of them will regenerate into a separate complete organism. In just a few weeks, a full organism can be
regenerated from a piece as little as one 279th of the already minuscule creature that
it’s been severed from. This is possible due to adult stem cells called
neoblasts, which account for 20 per cent or more of the total cells in the planarian flatworm. They reproduce rapidly to replace older cells. The existing tissue is remodeled to restore
the proportion and symmetry of the new worm that forms from a severed piece. In the 1950s two American biologists carried
out memory experiments on flatworms. These experiments revealed that there’s
a chemical basis for memory, which the researchers dubbed memory RNA. The working theory was that since ribonucleic
acid encodes information, it might also be used to record stimuli in neurons. The researchers trained planarian worms to
solve a simple maze consisting of bright lights and electric shocks. They then ground them up and fed them to untrained
planarian worms to see how they would fare in the maze. The experiment concluded that those which
had been fed trained worms associated the bright light with shock faster than those
that hadn’t. This was attributed to the hormones from the
ground animals which modified behavior in those fed to them. Even though the results of the experiment
were somewhat debatable, subsequent research proved that some memories can be stored outside
the brain. Although far from applicable in humans, the
ability to transfer memories indefinitely is typically regarded as a form of immortality. Number 2 Hydra
The Hydra is a type of fresh-water organism, native to tropical and temperate regions. These small creatures, which only grow to
about 0.39 inches in length, are among some of the most fascinating animals on Earth,
for a number of reasons. Their bodies consist of a simple adhesive
foot, called the basal disc and, at the free end, a mouth part surrounded by one to twelve
tentacles. Each of these tentacles is coated in specialized
cells with structures called nematocysts, which look like minuscule lightbulbs. They contain a triggering hair on the outside
and a coiled thread on the inside. Upon contact with prey, the nematocysts explosively
fire the dart-like thread, which contains neurotoxins. If many nematocysts are fired at once, their
prey can become paralyzed. Although these specialized attacks are interesting,
they’re not the most astonishing aspect about these creatures. The hydra is, so far, the closest known animal
to biological immortality. Named after a mythological creature that was
able to regrow its severed heads, the hydra doesn’t appear to die of old age or even
age at all. This is because its stem cells have an indefinite
capacity for self-renewal. They’re so potent that the Hydra can regrow
significant parts of its body, in case of an accident. When the hydra reproduces it typically grows
tiny clones of itself on its body, which then separate as they reach maturity. Three distinct stem cell populations are used
to replicate the tissues which form a fully functioning animal. All of them have a protein in common called
‘forkhead box O’ also known as FoxO. It’s believed to be the key factor behind
the Hydra’s immortality. There are hopes in the scientific community
that, by better understanding the Hydra, humans will one day never have to worry about aging. Number 1 Leopard Lungfish
Leopard Lungfish, also known as marbled lungfish, are found in swamps, floodplains and river
deltas throughout Africa. Their bodies can grow to nearly 7ft in length,
with long tails that taper at the end. Leopard lungfish also have very long and thin
pectoral and pelvic fins, which are used to glide through the water. They draw their common name from the dark
slate gray splotches that cover their fins and bodies, creating a marble or leopard-like
pattern. These remarkable creatures have the largest
known genome of any vertebrate. At 133 billion base pairs, the leopard lungfish’s
genome is also among the largest of any organism on Earth. Furthermore, studying the habits of this lungfish
may provide a solution for unlocking suspended animation in humans. That’s because the lungfish can live on
land, in riverbeds and other areas, that have no freshwater available, for up to 5 years. The fish will burrow into the ground to form
an air bubble, which it breathes out of, as it enters a dormant state called aestivation. They slow down their biological clock, surviving
in a low energy state in which they don’t need sustenance. Researchers, who’ve studied the leopard
lungfish in its dormant state, have noticed that it up-regulates genes related to detoxifying
waste and down-regulated genes related to blood coagulation. This means that it simultaneously stops the
build-up of harmful products in the liver as well as conserving energy. Once freshwater is available again, the fish
emerges from its cocoon to resume feeding and mating. It’s believed that it can repeat this cycle
indefinitely. Replicating this ‘suspended animation’
in humans would allow astronauts to enter hibernation during long space missions and
doctors to buy more time when operating on patients in critical condition. Thanks for watching! Which of these potentially immortal creatures
did you find most interesting? Let us know in the comment section below!
