Humans may be living longer than ever. But, our measly 71-year average pales in comparison to some of the sea creatures of the deep. Beneath the waves, animals can live for hundreds if not thousands of years – redefining the meaning of OAP.
From bowhead whales to sea urchins, koi fish to quahog clams, many sea creatures live to some truly incredible ages. But which ocean-dwellers live the longest? And what’s the secret to their astonishing longevity?
Here, we’re exploring the longest-living creatures in our seas. Aiming to give you the lowdown on why they live as long as they do.
Koi Fish
Koi fish may be one of the world’s best-loved pond and aquarium species. However, they have a secret: they’re one of the longest-living carp species in the world. Usually, koi live 25-30 years, but there have been several reports of fish living much longer. Like up to 200 years, kind of longer.
One such koi was the famous ‘Hanako’. A famed Japanese Koi, believed to have lived up to 226 years old. Following her death in 1977, researchers studied the growth rings on Hanako’s scales, revealing her true age. It’s not clear how Hanako lived so long, but she certainly survived through some incredible history. From the formation of the USA to the fallout of both World Wars.
Longfin Eel
Eels are surprisingly long in the tooth, with many of these sea creatures living 50+ years. This is primarily due to the slow rate at which they grow. They don’t reach full maturity quickly unlike other marine creatures.
The longfin species is the perfect example of an eel’s longevity. These slow-growing ray-finned fish are native to Australia and New Zealand. They have an average lifespan of 60 years, with the oldest-known longfin eel reaching 106 years old. It’s amazing to think that, despite their rudimentary design and anatomy, these primordial bottom-dwellers can sometimes outlive humans.
Bowhead Whale
While whales have a lot to contend with in the ocean, these grand mammals can really rack up the years. The bowhead whale, in particular, is a real stick-around. Scientists agree that many Bowheads live over 200 years – making them one of the longest-living mammals on Earth.
According to recent studies into the longevity of bowhead whales. Scientists think they may have discovered the secret behind the species’ long life. Studies into the bowhead’s genome reveal that they remain disease-free considerably longer than other whale species. That they may have developed a unique way to fend off ageing and promote cell repair. Clever stuff.
Red Sea Urchin
Although they may not look it, sea urchins are very much alive. Characterised by their imposing spiny shells, these weird creatures can live phenomenally long lives at staggering depths – with the red sea urchin being among the longest-living urchin species.
Native to the Pacific Ocean, particularly in North America, red sea urchins have an average lifespan of 200 years – meaning they’re almost as old as the country they inhabit. The secret to their long life comes down to the minimal energy they consume, as well as the slow rate at which they grow and develop.
Greenland Shark
Often described as dinosaurs on Earth, Greenland sharks are an ancient shark species native to the cold Atlantic waters of Greenland, Iceland and the Arctic. These primaeval-looking sea creatures regularly live 200+ years, with some of the oldest known examples living 400 years – placing them among the longest-living vertebrates in the world.
What’s the secret to Greenland sharks’ long lifespan? Researchers agree it’s all down to the rate at which they grow, with the average shark not reaching full maturity until they’re a century old! That’s like being born in 1920, and not being allowed to vote until this year! It also has a lot to do with the cold waters they’re native to, which slows metabolism and cell degeneration.
Quahog Clam
If you thought Greenland sharks were old, wait until you hear about quahog clams, one of the ocean’s oldest crustaceans. Some of these hard clam species, native to North and Central America, are calculated to be over 400 years old. Meaning that they were around before the start of the English Civil War!
Indeed, the historical significance of quahog clams wasn’t lost on researchers. They named one of the oldest examples ‘Ming’. In reference to the Ming Dynasty which ruled China from 1368 to 1644. It’s certainly impressive to think of all the historic moments these simple sea creatures have lived through.
Orca
Everyone knows that orcas are among the smartest marine mammals in the ocean. But, did you know that they’re also some of the longest-living? Some alive today are believed to be over 100 years old. It’s theorised, that the secret to their longevity lies within their ‘pod’ mentality.
Orcas live in pods, overseen by a matriarch. Offspring protect the matriarchs throughout their lives. This means the matriarch tends to live the longest. For the past decade, researchers in the US have been tracking a pod led by ‘Granny’. It’s estimated Granny is a healthy 104 years old.
Deep-Sea Sponge
You may think we’re bending the definition of ‘creature’ a little here but deep-sea sponges are very much alive. And boy, do they grow to be old. According to some studies, deep-sea sponges can reach thousands of years old. The oldest known example is estimated to have reached the grand age of 11,000!
Deep-sea sponges grow at tremendous depths, forming sprawling and often complex structures. These structures, in turn, attract the attention of the creatures’ preferred prey, plankton. Some of the largest known deep-sea sponges are about the size of a car. With an average lifespan of over 2,000 years – meaning they’ve been around since the time of the Romans.
Immortal Jellyfish
The term ‘immortal’ gets bandied around a lot in superhero movies. But until recently, the notion of eternal life was nothing more than fiction. However, back in the 1980s, scientists made a startling discovery. It defied what we thought we knew about everlasting life: the immortal jellyfish.
The immortal jellyfish (turritopsis dohrnii) is a small jellyfish that is classified as biologically immortal. Found in tropical waters, the secret to this creature’s eternal life lies in its ability to revert to sexual immaturity. Wherein it effectively clones itself. Given its amazing and seemingly endless lifespan, the immortal jellyfish is considered one of the world’s most important marine species for biological and pharmaceutical research.
So, there you have it, a look at some of the longest-living marine creatures in our oceans. Looking for more from Blue Planet Aquarium? Head to the blog for more fun features and guides. To plan your visit to our aquarium, visit the homepage.