Sea Monsters

Part of the Mythic Creatures exhibition.

Kraken model
© AMNH / D. Finnin

Why do people see sea monsters?

The open ocean can be a terrifying place. Miles from shore on storm-tossed seas, with nothing but water in all directions--including straight down--a sailor or fisherman cannot help but wonder what lurks in the depths. When the oceans were still unexplored, these fears often took the form of imaginary monsters.

Many sea monsters include features from living animals. A large tentacle becomes part of a monstrous sea serpent or many-armed kraken: The eye sees a fragment, the mind fills in the rest. A blend of tall tales, mistaken identity, and resonant cultural symbols, stories of sea monsters often reveal more about the minds of the imaginers than they do about the natural world.

"It was a giant squid twenty-five feet long. It was heading toward the Nautilus, swimming backward very fast.... We could clearly make out the 250 suckers lining the inside of its tentacles, some of which fastened onto the glass panel of the lounge. The monster's mouth--a horny beak like that of a parakeet--opened and closed vertically.... What a whim of nature! A bird's beak in a mollusk!"

--Jules Verne, Twenty Thousand Leagues Under the Sea, 1870

Many-armed monster

The mythical kraken may be the largest sea monster ever imagined. Some stories described it as more than 2.5 kilometers (1.5 miles) around with arms as large as ship's masts. Perhaps based on sightings of giant squid tentacles, this multi-armed monster rarely attacked humans, preferring to stay in deep water where it feasted on fish. The chief dangers came from being too close when it surfaced--or too close when it sank, as a boat could be sucked down in the whirlpool created when it submerged.

  • Described in Scandinavian stories dating back to about AD 1180, the kraken was said to live near Norway and Iceland.
  • Long, flexible arms or tentacles like those of a giant squid or octopus.
  • Limbs so large they looked like a ring of islands.
  • Ate huge quantities of fish, which it lured with an enticing smell; fisherman would rush over, hoping to snare a share of the kraken's catch.
  • When a kraken surfaced, a shimmering cascade of fish might be seen tumbling down its back.

So They Say

"Below the thunders of the upper deep
Far, far beneath in the abysmal sea
His ancient, dreamless, uninvaded sleep
The Kraken sleepeth...
There hath he lain for ages and will lie...
Until the latter fire shall heat the deep;
Then once by man and angels to be seen,
In roaring he shall rise and on the surface die."

--Alfred, Lord Tennyson, British poet (1809-1892)

The famous "Surgeon's photo" of the Loch Ness Monster, 1934, believed to be a forgery
© Hulton Archive/Getty Images

Still Hoping

Stories that appeal to the imagination are hard to dispel--especially when there is no way to disprove them. Take the Loch Ness Monster, which is said to inhabit a lake in northern Scotland. Though investigators have searched for the monster with underwater cameras and sonar for decades--and some alleged evidence was exposed as a fraud--people still flock to the site, hoping for a glimpse of "Nessie."

Giant Squid

  • The largest eyes of any living creature: Each eye can be as large as a human head.
  • Sharp, parrot-like "beaks" provided the first hard proof of their existence. In 1853, a giant squid washed ashore in Denmark and was cut up for bait, but its beak was saved, leading to recognition of the genus Architeuthis in 1857.
  • A deep-ocean creature rarely seen near the surface; most sightings involve dying animals or corpses that wash up on shore.
  • Suckers can leave scars on whales.
Giant Squid Tentacle
© AMNH / D. Finnin

Giant Squid Tentacle

This jar contains a two-meter (six-foot) tentacle from a giant squid (Architeuthis kirkii). The complete specimen was caught by fishermen near New Zealand in 1997 and shipped frozen in ice to the American Museum of Natural History in New York. The entire animal measured 7.5 meters (25 feet), which is not even large by giant squid standards: Some can grow to 20 meters (about 70 feet).

Giant Squid

Five hundred years ago, sailors in northern Europe told of an amazing creature: A monster bigger than a man with numerous long, snakelike arms covered with suckers for grabbing prey. Evidence for this so-called devil-fish included bits of giant tentacles found in whale stomachs and vicious battle scars left on the skin of whales by its suckers and claws. Eventually, in the 1850s, scientists recognized the devil-fish as an authentic animal--the giant squid.

So They Say

In 1873, fishermen presented a squid arm--supposedly hacked off the animal when it attacked the men's boat--to the Reverend Moses Harvey, a prominent Canadian naturalist. Harvey wrote about the 5.8-meter (19-foot) long arm:

"I was now the possessor of one of the rarest curiosities in the whole animal kingdom--the veritable tentacle of the hitherto mythical devil-fish, about whose existence naturalists had been disputing for centuries. I knew that I held in my hand the key of a great mystery, and that a new chapter would now be added to Natural History."

Still Lurking

After the success of Jaws, American author Peter Benchley frightened readers all over again in 1991 with his bestselling novel Beast, about a giant squid. In the novel, the squid attacks several people--something yet to occur in reality. Benchley wrote, "In the frenzy of a kill, the tentacles would spring forward, like tooth-studded whips." Some squids do have claws on their arms, but never in the center of their suckers.

What's Bigger Than a Giant Squid?

The giant squid is not the biggest squid. Scientists have known of an even larger species since at least 1925, but no adult specimen had been found in one piece until 2007, when fishermen hauled one up near New Zealand. Dubbed the "colossal squid," it is thought to be the largest living creature without a backbone. Classified in its own genus, Mesonychoteuthis hamiltoni outweighs all of the eight giant squid species in the genus Architeuthis.

Mythic Kraken

Hundreds of years ago, European sailors told of a sea monster called the kraken that could toss ships into the air with its many long arms. Today we know sea monsters aren't real--but a living sea animal, the giant squid, has 10 arms and can grow longer than a school bus.

Sea Monsters

"On the 6th of July 1734, when off the south coast of Greenland, a sea-monster appeared to us, whose head, when raised, was on level with our main-top. Its snout was long and sharp, and it blew water almost like a whale; it has large broad paws; its body was covered with scales; its skin was rough and uneven; in other respects it was as a serpent; and when it dived, its tail, which was raised in the air, appeared to be a whole ship's length from its body."

--Hans Egede, Norwegian missionary, later bishop of Greenland

Discovering Monsters

When European explorers like Christopher Columbus set out on their voyages of discovery in the 1400s and 1500s, they were literally sailing into uncharted waters. Sea monsters were a concern for them, and frightening rumors ran rampant. Sailors' tales were sometimes the only first-hand information available about ocean animals. These stories ranged from accurate observations to honest mistakes to outright tall tales, with no way for even the most objective naturalist to separate fact from fiction. The meticulous drawings of sea monsters in European natural history books from the 1500s and 1600s reveal the overlap between science and legend at that time.

The Age of Exploration

The period from the 1400s to the 1600s in Europe is sometimes called the "Age of Exploration." Adventurers set sail from western Europe seeking wealth, power--and knowledge. Before then, Europeans who wrote and illustrated natural history books based them mostly on older books, often deferring to Greek masters such as Aristotle. But as a new view of knowledge arose in Europe emphasizing first-hand observation, data from traveling naturalists became increasingly important. In this transitional era, an author might present a newly discovered animal on the same page as a mythical creature.

Don't Believe Your Eyes

Many sincere sea serpent sightings were later debunked as cases of mistaken identity. For instance, several "sea monster" carcasses turned out to be partially decayed basking sharks, an immense fish that grows to 9 meters (30 feet). Other examples of mistaken identity include a "baby sea serpent" that proved to be a deformed blacksnake, and enormous serpents that turned out to be a mass of floating seaweed.

The oarfish (Regalecus glesne) can reach 8 meters in length. Eastern Pacific Ocean.
© N. Wu/Minden Pictures

Sea Serpents Unmasked?

Several pictures of sea serpents on old maps appear to be based on sightings of the oarfish, or ribbon-fish (Regalecus glesne). A long, eel-shaped fish that grows to 11 meters (36 feet), the oarfish has a crest of bright red spines on its head and a spiny dorsal fin running down its entire back.




Hippocampus illustration from a 1563 book by Conrad Gesner
American Museum of Natural History Library Services

Parallel Universe

A picture from a 1563 book by Swiss naturalist Conrad Gesner shows a hippocampus, a sea creature with a horse's head. According to a theory still popular at that time, every animal found on land had its counterpart in the ocean.




Illustrations from a 1557 book by Konrad Lykosthenes, a German encyclopedia writer
American Museum of Natural History Library B-6

Book of Sea Life

Konrad Lykosthenes, a German encyclopedia writer, published a book in 1557 showing the dangerous monsters awaiting sailors on the open seas, including an oversized lobster shown spearing a man with its antenna (M). Although these monsters are fanciful, many include elements of real animals.




Map of Iceland: Several sea monsters cavort in the waters off Iceland in this 1585 map drawn by Andreas Velleius.
© Courtesy Strachan and Vivian Donnelley

Map of Iceland

Several sea monsters cavort in the waters off Iceland in this 1585 map, titled Islandia, drawn by Andreas Velleius. Shown in the lower left are vaccae marinae, the Latin name for "sea cows," and an animal with a horse's head and a fish's tail known as a hippocampus.




"Sea monk," from a 1575 book by Swiss naturalist Konrad Gesner.
American Museum of Natural History Library RF-29-E

Fish Book

Among the most startling depictions of sea creatures in the 1500s are the "sea monk" and "sea bishop," illustrated here in a 1575 book by Swiss naturalist Konrad Gesner. Supposedly captured in Denmark and Germany, these mysterious sea creatures have body parts that mimic the characteristic robes and bishop's hats of Catholic clergymen.







"Sea bishop," from a 1575 book by Swiss naturalist Konrad Gesner.
American Museum of Natural History Library RF-29-E

Family Resemblance

In 1855, a Danish zoologist, Japetus Steenstrup, proposed that the fabled sea bishop was actually a large squid. He offered a picture illustrating how the misunderstanding could have occurred.