Few creatures have captured the imagination of artists, writers, scientists, mathematicians, and paleontologists as much as the chambered nautilus. Nautili are classified as within Cephalopoda, the same family as octopuses, squid, and cuttlefish. Unlike their soft-bodied cousins, nautili are the only cephalopods that protect themselves with a chambered shell. This shell has two major features that have fascinated humans since the Nautilus’ discovery. These are the pearly, luminescent nacre that lines the inside of the shell, and the iconic compartments spiraling outwards in near-perfect symmetry. As early as the Renaissance, its shell can be found in jewelry, furniture, art, and decoration. However, our obsession with harvesting the nautilus’ shell has caused the species irrevocable harm in the past few centuries: nautilus populations today are dangerously low, teetering at near-extinction due to overfishing, pollution, and environmental degradation. It is more important than ever to understand the nautilus before its memory is relegated to curios kept on display.
Nautili are found in and around the coral reef slopes of the Indo-Pacific, feeding on a wide variety of crustaceans, small fish, and invertebrates. Beyond their beauty, nautili shells serve many functions: they provide protection, camouflage, and work to maintain a nautilus’ buoyancy. The chambers work like the ballast tanks in a submarine, filling and expelling water to adjust the nautilus’ depth. Most deep-water species have evolved under extreme pressure and will perish if brought to the surface; the Nautilus is an exception to this rule. Although nautili are thought to be primarily deep-sea animals, usually preferring to dwell at about 2,000 feet below sea level, they are often seen rising in the water column to eat and are not affected by the extreme swings in pressure.
Nautili are some of the oldest unchanged modern animals known to paleontology. They are often dubbed “living fossils”, having extremely similar relatives dating back over 500 million years, to the late Cambrian period. Like sharks, horseshoe crabs, and alligators, the evolutionary design of nautili has differed little since the time of the dinosaurs. Ancestors of the Nautilus have survived mass extinctions, ice ages, and meteor strikes–but the greatest challenge in their half-a-billion-year history has proven to be environmental interference by humans.
Recently, scientists have grown alarmed about the state of nautilus populations. Because they are deep-sea dwellers, their numbers are difficult to track. But we can estimate the damage done by examining the number of shells harvested and traded within the United States yearly: over 100,000. As nautili face a rapidly changing ocean, they also contend with human greed and brutality, as hundreds of thousands are stolen from their habitats each year to be sold for decoration. Certain animals might be able to bounce back from predation that intense, but nautili are slow to mature and have a comparatively short reproductive cycle: they only reach sexual maturity at age 15. Most nautili live to about 20, so they are only reproducing for the final quarter of their lives. In an already difficult and unpredictable environment, the odds are stacked against nautili reaching sexual maturity in the best of circumstances.
In addition to poaching, nautili must contend with a rapidly changing environment. Warming ocean temperatures are bleaching corals around the world at an alarming rate. As nautili spend their lives in the deep water around the base of coral beds, they will find their prey to be more and more scarce as corals die away. Our oceans are more polluted than ever, with plastics now infiltrating the deepest parts of the ocean. Preventing the loss of this precious and ancient species requires a multifaceted approach: pollution and carbon dioxide output must be curbed, and nautili must receive further protections under CITIES or the Convention on International Trade in Endangered Species.
Nautili are especially vulnerable to overfishing and environmental degradation due to their low mobility, their slow maturity, and short reproductive window. We must act now as stewards of our oceans to ensure that these creatures receive the protections they deserve.
To learn more about the nautilus’ natural habitat, please visit our Coral Reef Ecosystems page at:
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A lovely example of the many pieces of literature created about nautili is The Chambered Nautilus, a poem from the mid-nineteenth century by author Oliver Wendell Holmes Sr:
The Chambered Nautilus by Oliver Wendell Holmes Sr.
This is the ship of pearl, which, poets feign,
Sails the unshadowed main,—
The venturous bark that flings
On the sweet summer wind its purpled wings
In gulfs enchanted, where the Siren sings,
And coral reefs lie bare,
Where the cold sea-maids rise to sun their streaming hair.
Its webs of living gauze no more unfurl;
Wrecked is the ship of pearl!
And every chambered cell,
Where its dim dreaming life was wont to dwell,
As the frail tenant shaped his growing shell,
Before thee lies revealed,—
Its irised ceiling rent, its sunless crypt unsealed!
Year after year beheld the silent toil
That spread his lustrous coil;
Still, as the spiral grew,
He left the past year’s dwelling for the new,
Stole with soft step its shining archway through,
Built up its idle door,
Stretched in his last-found home, and knew the old no more.
Thanks for the heavenly message brought by thee,
Child of the wandering sea,
Cast from her lap, forlorn!
From thy dead lips a clearer note is born
Than ever Triton blew from wreathèd horn!
While on mine ear it rings,
Through the deep caves of thought I hear a voice that sings:—
Build thee more stately mansions, O my soul,
As the swift seasons roll!
Leave thy low-vaulted past!
Let each new temple, nobler than the last,
Shut thee from heaven with a dome more vast,
Till thou at length art free,
Leaving thine outgrown shell by life’s unresting sea!
Add noise pollution to coral reef life.