What Is Sea Cucumber? Everything You Need to Know

It looks a little strange. It lives on the ocean floor. And in parts of Asia, it has been served at important dinners and celebrations for centuries.

Meet the sea cucumber.

Despite the name, sea cucumbers aren’t vegetables—or even fish. They’re marine animals belonging to a group called echinoderms, making them relatives of sea stars and sea urchins.

And they’re much more interesting than their appearance might suggest.

So, What Exactly Is a Sea Cucumber?

Sea cucumbers are soft-bodied marine animals that live primarily on the seafloor.

More than 1,000 species of sea cucumber have been identified around the world, ranging from shallow coastal environments to the deep ocean. Depending on the species, they can vary dramatically in size, color, texture, and appearance.

Their scientific class is Holothuroidea, which belongs to the phylum Echinodermata—the same family tree that contains sea stars, brittle stars, sand dollars, and sea urchins.

So despite occasionally appearing on seafood menus alongside fish and shellfish, a sea cucumber is neither.

The Ocean’s Cleanup Crew

Sea cucumbers spend much of their lives moving slowly across or underneath the ocean floor.

Many species consume sediment and organic material, extracting usable nutrients before passing the remaining material back into their environment.

Think of them as tiny processors constantly working their way across the seafloor.

This seemingly simple behavior can play an important role in marine ecosystems by recycling nutrients and altering sediments.

They Can Literally Eject Their Organs

This is where sea cucumbers get weird.

When threatened, certain species of sea cucumber can expel portions of their internal organs from their bodies.

Yes, really.

The behavior is called evisceration.

Even more remarkably, the sea cucumber can subsequently regenerate the lost tissues and organs.

This regenerative ability has made sea cucumbers an interesting subject for researchers studying tissue regeneration and wound repair.

People Have Been Eating Them for Centuries

Sea cucumber isn’t a new wellness trend.

It has a long culinary history, particularly across China and other parts of East and Southeast Asia.

In Chinese, sea cucumber is commonly called 海参 (hǎishēn).

The name literally combines the characters for “sea” (海) and “ginseng” (参)—hence the frequently used English nickname “sea ginseng.”

Historically, certain varieties of sea cucumber became prized foods and could be served at banquets, celebrations, and other special occasions.

Today, dried sea cucumber can still command surprisingly high prices depending on its species, size, origin, and quality.

Why Does Traditional Sea Cucumber Take So Long to Prepare?

One reason many Americans have never prepared sea cucumber at home is simple:

It’s a process.

Traditional dried sea cucumber often needs to be repeatedly soaked and rehydrated before it reaches the texture required for cooking. Preparation methods vary, but the process can extend over several days.

That’s perfectly reasonable for an elaborate banquet.

It’s considerably less convenient on a Tuesday morning.

What’s Actually in Sea Cucumber?

Sea cucumber is notable for its protein content and contains a variety of naturally occurring compounds that researchers have investigated, including:

• Proteins and amino acids
• Collagen and other structural proteins
• Fatty acids
• Minerals
• Saponins
• Other bioactive compounds

The exact nutritional composition varies substantially by species, body part, environment, and processing method.

That last point matters.

“Sea cucumber” isn’t one standardized ingredient. Different species—and even different tissues from the same animal—can have different nutritional profiles.

And Then There’s the Gonad

Here’s a part of sea cucumber biology most people have never encountered.

Like other animals, sea cucumbers have reproductive organs called gonads.

Sea cucumber gonads have their own nutritional composition and have been studied separately from the body wall that makes up much of the sea cucumber traditionally eaten as food.

That’s why sea cucumber powder and sea cucumber gonad powder shouldn’t automatically be treated as interchangeable ingredients.

They’re derived from different tissues.

We’ll explore that distinction in a separate article.

Why Powder Sea Cucumber?

Traditional sea cucumber is culturally significant and fascinating—but it isn’t particularly convenient.

Powder offers another way to use the ingredient.

Removing water and processing sea cucumber into a powder makes it possible to incorporate measured amounts into foods, beverages, capsules, or other formulations without the multi-day preparation associated with dried whole sea cucumber.

It’s an old ingredient in a decidedly modern format.

From Sea Cucumber to SEACURO

At SEACURO, we’re interested in an overlooked part of marine nutrition: taking ingredients with long histories and making them easier to understand and use today.

Sea cucumber happens to be a particularly fascinating place to start.

It’s an animal that helps process the ocean floor, can regenerate internal organs, is related to sea stars rather than fish, has been eaten for centuries, and is still unfamiliar to much of the Western world.

Not bad for something that looks like a cucumber at the bottom of the ocean.

Next: What Is Sea Cucumber Gonad? A Guide to the Most Overlooked Part of the Sea Cucumber