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Meet the 7 Longest Living Ocean Animals

Learning about lifespans in the deep blue sea

immortal jellyfish
© MUZINA_SHANGHAI/FLICKR

What is the secret to living a long life? Often centenarians will share their secrets, including eating oatmeal each day, staying single, exercising or having a positive outlook on life. Whether or not you believe those theories, one thing is for certain: Humans have some serious catching up to do compared with other animal lifespans. The oldest living human lived to be only 122 years old (cue the Greenland shark laughing!).

But how do these long-living animals have a lifespan that is many centuries old? Scientists think it has to do with the animals’ metabolism, with size and habitat as contributing factors. Bigger animals tend to have a slower metabolism. And animals that live in frigid, cold habitats also tend to have a slower metabolism. The frigid waters of the Arctic make it possible for Greenland sharks to survive for centuries. Metabolic rate is thought to be inversely proportional to maximum lifespan, which means that species that live fast will die young while those that have a slower metabolic rate live slower and longer.

Fascinating!!

Without further delay, meet these seven ocean animals that have had more birthdays than almost every other creature on Earth.

Greenland Shark

Somniosus microcephalus

(300-500 years)

Greenland_shark_profilesm
© Hemming1952 / Wikimedia

Living in the cold Atlantic waters of Greenland, Iceland and the Arctic, Greenland sharks are often described as dinosaurs on Earth. Greenland sharks recently broke a record: Scientists discovered a 400-year-old female Greenland shark that set a new record for the oldest living vertebrate.

Ocean Quahogs (Clams)

Arctica islandica

(200-500 years)

ocean quahog clam
© NOAA Fisheries

Ocean quahogs are among the longest-living marine organisms in the world. The ocean quahog is a species of edible clam, a marine bivalve mollusk. Ocean quahogs live in the Atlantic and can live more than 400 years old. At 507 years of age, Ming the clam broke the Guinness World Record as the oldest animal in the world. Ming the clam was dredged off the coast of Iceland in 2006. Ming was born in 1499 and died in 2006—that age was calculated by counting annual growth lines in the shell.

Black Coral

Leiopathes glaberrima

(more than 4,000 years)

deep sea black coral
© NOAA Photo Library

The estimated lifespan of a black coral colony is 70 years. However, in March 2009 a deep-water species of black coral was discovered, and scientists estimate it was around 4,265 years old. Coral polyps are invertebrates belonging to a group of animals called Cnidaria. Other animals in this group include jellyfish and sea anemones. Coral reefs are made up of tiny organisms called polyps. The result is a colony of polyps that actually act as one organism.

Immortal Jellyfish

Turritopsis dohrnii

(immortal)

immortal jellyfish
© MUZINA_SHANGHAI/FLICKR

The immortal jellyfish is a species of jellyfish no bigger than a half centimeter that lives in seas across the world. Like other cnidarians, it has two forms: medusa (think classic jellyfish with bell-shaped body and multiple tentacles) and hydroid or polyp (the baby form, growing in a colony with other polyps on the ocean floor). Its unique ability to revert to this younger polyp form after reaching its fully grown state, thereby starting its life cycle anew, is what earns this jellyfish the title “immortal.”

Bowhead Whale

Balaena mysticetus

(more than 200 years old)

bowhead whale breaching
© Kate Stafford

Bowhead whales can live more than 200 years–making them one of the longest-living mammals on Earth. Bowhead whales live in the chilly Arctic and subarctic waters year-round. The bowhead is the fifth largest whale in the ocean, reaching up to 60 feet in length. Bowhead whales are among the heaviest animals on Earth with their weight between 75-100 tons. 

Rougheye Rockfish

Sebastes aleutianus

(200 years old)

drawing of rockfish
© Bulletin of the United States Fish Commission

The rougheye rockfish are among the longest-living fish and have a maximum lifespan of at least 205 years, according to the Washington Department of Fish and Wildlife. Their habitat is in coastal waters from California to Japan. Rougheye rockfish typically live at depths between 500 and 1,500 feet. They are found near the seafloor around caves and crevices. Rockfish are slow-growing, late-maturing and long-lived. Unfortunately, this also makes them highly vulnerable to overfishing. Recovering from fishing pressure is another thing rockfish do slowly.

Glass sponge

Farrea occa

(10,000 years or more)

glass sponge deep sea
© NOAA

Glass sponges in the class Hexactinellida are animals commonly found in the deep ocean. Sponges are firmly attached to the sea floor (with a few exceptions) for their entire adult lives. They survive by pumping water through their porous bodies to extract very small food particles and dissolved substances. Glass sponges grow in many shapes and sizes in the deep ocean. Glass sponge reefs were thought to have become extinct about 40 million years ago—they left fossil cliffs that can be found across Europe. In 1987, however, scientists discovered 9,000-year-old living glass sponge reefs in Canada—the only current reefs of their kind (that we know of).

An Ocean of Birthdays on the Horizon

As silly as this may sound, I genuinely wish I had the ability to interview one of these long-living creatures. What was it like in the ocean 500 years ago? How does it feel to be alive for that long? It truly is mind-boggling.

It’s certainly mind-bending to try to wrap your head around all of the historic moments these ocean animals have lived through. Ming the clam was alive during the Ming Dynastic (which ruled China from 1368 to 1644).

And scientists say that there are thousands more species of sponge and coral which have yet to be discovered!

The ocean and all its inhabitants are truly spectacular. It’s up to all of us to help protect them so they can celebrate hundreds or thousands more birthdays! Please make a donation to Ocean Conservancy to celebrate these creatures—give today and make a difference for the future of our ocean!

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