Scuba divers get to see incredible marine species that others can only see in pictures or on television. From the oldest deep sea creatures to bucket list pelagic encounters, the opportunities are endless. Not only that, but exploring the underwater world offers a chance to discover the most ancient animal species that have been around longer than we have!
Want to know which marine species has existed the longest? Here are 12 of the oldest marine species in the ocean you can still find under the surface today.
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1. Frilled shark
With strange eel-like features, this animal doesn’t look like many of the other sharks we’re familiar with today. It is a shark though; it’s just 150 million years old and hasn’t evolved much. Of all the prehistoric creatures that still exist, the frilled shark might be one of the weirdest marine species ever!
2. Tadpole shrimp
These tiny crustaceans have been around for more than 200 million years. The survival of these ancient ocean creatures may have to do with the fact that their eggs only hatch when the environmental conditions are favorable.
3. Coelacanth
Once thought to have gone extinct around the same time as dinosaurs, the coelacanths were rediscovered in 1938 off the coast of South Africa. Now over 360 million years old, these giant, prehistoric marine animals are still considered endangered and are rarely seen.
4. Sturgeon
The sturgeon is actually a family of fish that includes 27 species. They are about 200 million years old and also have a long lifespan. Some live to be 100 years old! However, overfishing and the illegal caviar trade means this oldest fish species is also one of the most endangered.
5. Horseshoe shrimp
The horseshoe shrimp is a great example of a “living fossil” – one of the oldest species on Earth that still exists today. Even after 200 million years, it seems this creature’s appearance hasn’t changed a bit. In fact, this primitive crustacean lacks eyes and is barely the size of a sesame seed!
6. Greenland shark
Sharks are one of the most popular marine species today, but did you know the earliest fossils date around 450 million years? Even more impressive is the elusive, deep-sea Greenland shark, which is one of the oldest living species. It’s believed they can reach over 500 years old!
7. Lamprey
The creepy-looking lamprey looks like something straight from a horror movie. It’s shaped like an eel, but these 450-million-year-old animals are actually parasites. They’re bloodsuckers that use their disc-shaped suction mouths to latch onto other marine species.
8. Nautilus
The nautilus has survived through 500 million years. Unfortunately, despite being one of the oldest animal species, it is now in danger of becoming extinct. The nautilus’s unusual and unique shell makes them a prime target for shell collectors.
9. Horseshoe crab
Just like the horseshoe shrimp, the horseshoe crab has remained unchanged throughout its existence – which has been a long 450 million years. They’re actually more closely related to spiders and scorpions than crabs, and, like their relatives, they even glow under UV light!
10. Sponges
No one’s exactly sure how old the sponge is, but scientists do know that one species dates back at least 890 million years. That’s old enough to make them one of the oldest living species on Earth still around today!
11. Jellyfish
Slightly over 500 million years old, jellyfish are one of the few marine species affected by climate change in a positive way. Jellyfish populations have actually increased in warmer waters. Who knows, maybe they’ll live another 500 million years!
12. Baleen whales
This toothless family of whales includes humpback, blue, and bowhead. A recent discovery of a 36-million-year-old fossil uncovered even more of these ancient animals’ history. They are relative newcomers compared to others on the list, but still one of the oldest marine mammals.
13. Crinoids
Also known as sea lilies, Crinoids first appeared approximately 480 million years ago! Today, they inhabit much deeper ocean environments while their fossilised stems can be found in rocks across the globe. Their feathered ‘arms’ still play a vital role in the ocean ecosystem, filtering plankton from the ocean.
14. Hagfish
Dating back to 300 million years ago, Hagfish are one of the oldest living vertebrate relatives! These are eel-like creatures, living by clearing up decaying matter from deep seabeds and cleaning the surrounding ecosystem. An interesting behaviour of the Hagfish is its production of extensive slime when threatened.
15. Sea Anemones
Surpassing the Hagfish, sea anemones date back over 500 million years ago! Today, most of us know them fondly as “Nemo’s home“, thanks to their symbiotic nature. Sea Anemones form symbiotic relationships with other marine species, providing both food and protection while also managing to paralyze prey with their venomous tentacles if threatened.
16. Tuatara
While not specifically a marine species, the Tuatara reptile lives within sea-dependent ecosystems, and has done so for around 250 million years. Tuatara have an interesting appearance of a third eye on the top of their heads, often absent in other living vertebrates.
Protect the ocean’s oldest marine species
These fascinating marine species have been on the planet for millions of years, but sadly many of them are now at risk of extinction. Factors such as overfishing, illegal trade, and habitat loss mean we could lose these ancient creatures forever. On your next scuba dive, make it your mission to find – and protect – one of these 12 amazing animals!
Haven’t got a scuba certification yet? PADI is a passionate community of underwater enthusiasts motivated to protect what is worth saving – including the oldest species of marine life on the planet, from nautilus to sharks. Learning to dive will give you the tools you need to help protect the ocean and experience nature unfiltered.
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