Sea cucumber has been eaten across East and Southeast Asia for centuries, prized for its unusual texture and perceived health benefits rather than any strong flavor of its own. Dried and rehydrated sea cucumber remains a luxury ingredient in Chinese, Korean, Japanese, and Malaysian cooking, while the global trade now reaches markets in Europe and North America. The story of sea cucumber as food is surprisingly layered, touching on centuries-old trade routes, collagen-rich nutrition, elaborate preparation rituals, bioactive compounds that interest medical researchers, and a booming aquaculture industry that raises its own set of questions about what these animals themselves eat.
Centuries of Trade and Demand
The commercial appetite for sea cucumber, known in its dried form as trepang or bĂŞche-de-mer, stretches back at least 300 years. Chinese markets have long treated it as a high-value commodity, and the town of Makassar in South Sulawesi became the historical center of a specialized fishing and trading network that connected island communities across Southeast Asia to buyers in China.1PubMed Central. The history of Makassan trepang fishing and trade That trade helped transform coastal economies for generations, but the industrialization of fishing in the twentieth century led to severe overharvesting of wild populations worldwide. Today, dozens of sea cucumber species are commercially fished or farmed, with prices for premium dried specimens reaching hundreds of dollars per kilogram depending on the species, size, and processing quality.
Preparation and Texture
If you have never encountered sea cucumber in a kitchen, the preparation process can seem daunting. Most sea cucumber sold internationally is dried, which shrinks the animal into a hard, dark lump that bears little resemblance to the soft creature on the ocean floor. Rehydrating it is a multi-day affair. Research on dried specimens soaked in distilled water found that after two full soaking cycles, the animal’s weight increased to roughly 7.6 times its original dried weight, reaching a water content of about 94.5%, nearly matching raw sea cucumber.2ResearchGate. Effects of soaking conditions on the texture of dried sea cucumber During soaking, minerals leach out fastest, followed by glycosaminoglycans (a type of complex sugar important to the animal’s connective tissue), and then collagen.
The result is a gelatinous, mildly chewy product that absorbs the flavors of whatever sauce or broth it is cooked in. Sea cucumber has almost no taste on its own. Its appeal is textural: a slippery, slightly springy bite that Chinese culinary tradition classifies alongside other prized “mouthfeel” ingredients like shark fin and fish maw. It shows up braised in oyster sauce, simmered in hot pots, stir-fried with vegetables, or served in elaborate banquet soups. In Japan, raw sea cucumber (namako) is sometimes sliced thin and dressed with vinegar as a cold appetizer. Korean cuisine uses it in stir-fries and stews. The drying method itself matters less than you might expect for the final texture: studies comparing freeze-drying, hot-air drying, and microwave drying found that the rehydration rate and sensory characteristics were similar across all three methods.3Journal of Food Processing and Preservation. The effect of different drying methods on chemical composition, fatty acid, and amino acid profiles of sea cucumber (Holothuria tubulosa Gmelin, 1791)
Nutritional Profile
Sea cucumber’s reputation as a health food is not empty marketing. The animal is characterized by high protein and low fat, which has made it a subject of growing research interest.4ACS Publications (Journal of Agricultural and Food Chemistry). Production of Bioactive Peptides from Sea Cucumber and Its Potential Health Benefits: A Comprehensive Review The body wall, which is the main edible portion, is largely collagen, and its amino acid profile reflects that: rich in glycine and proline, the building blocks of connective tissue. It also contains minerals like calcium, magnesium, and zinc, though the soaking process does wash some of those away as noted above.
Where things get more interesting is in the bioactive compounds. Sea cucumber tissue contains fucosylated chondroitin sulfate, a complex sugar chain that has drawn attention for its anticoagulant properties. Research on the species Thelenota ananas showed that this compound’s blood-thinning activity varies with its molecular weight and fucose content, and it works partly by inhibiting a specific step in the clotting cascade.5Journal of Traditional and Complementary Medicine. Medicinal and health benefit effects of functional sea cucumbers Low-molecular-weight fragments of the same compound have even shown activity against HIV replication in laboratory settings. Peptides derived from sea cucumber protein have been studied for antioxidant, anti-diabetic, immune-modulating, and anti-cancer properties, though most of this work remains in cell cultures and animal models rather than human clinical trials.6ACS Publications (Journal of Agricultural and Food Chemistry). Production of Bioactive Peptides from Sea Cucumber and Its Potential Health Benefits: A Comprehensive Review
It is worth being realistic here. Eating braised sea cucumber at dinner is not the same as taking a purified bioactive compound in a clinical dose. The concentrations of these substances in a normal serving are far lower than what researchers use in experiments, and digestion further alters them. Traditional medicine systems in China, Korea, and Southeast Asia have valued sea cucumber for wound healing, joint health, and general vitality for generations, and the laboratory findings are at least consistent with those traditions, but they do not yet prove that eating the animal delivers those specific benefits in humans.
What Sea Cucumbers Themselves Eat
Understanding what sea cucumbers eat in the wild matters for two reasons: it explains why they play such an outsized ecological role on coral reefs, and it shapes how the aquaculture industry feeds farmed animals. Most sea cucumber species are deposit feeders, meaning they crawl along the ocean floor scooping up sediment and extracting organic particles from it. A broad review of wild sea cucumber nutrition concluded that these animals selectively target fine, organically rich particles, and that bacteria are a particularly important component of their diet across multiple taxonomic orders.7Wiley Online Library / Biological Reviews. Sophistication in a seemingly simple creature: a review of wild holothurian nutrition in marine ecosystems
The selectivity is measurable. In juvenile Australostichopus mollis, nitrogen enrichment in the foregut exceeded 100% compared to the surrounding sediment, and carbon enrichment reached as high as 145%, meaning these animals are very good at picking out the nutritious bits from what looks like undifferentiated mud.8Journal of Experimental Marine Biology and Ecology. Organically selective movement and deposit-feeding in juvenile sea cucumber, Australostichopus mollis determined in situ and in the laboratory Juveniles also actively moved toward patches of sediment with higher organic content, though their ability to distinguish between sediment qualities plateaued once organic matter exceeded about 3%.
Not all sea cucumbers feed this way. Some species are suspension feeders, capturing particles drifting through the water column. The armored sea cucumber Psolus chitinoides uses specialized adhesive bumps on its feeding tentacles to snag suspended matter, with warty papillary cells secreting a sticky substance that traps food particles.9Journal of Experimental Marine Biology and Ecology. Suspension-feeding mechanisms of the armoured sea cucumber Psolus chitinoides Clark These tentacles even have sensory cells that help detect food in the water. The distinction between deposit feeders and suspension feeders matters for aquaculture, since the feeding method determines what kind of food a farmed species needs.
Reef Janitors and Sediment Recyclers
Sea cucumbers are sometimes called the earthworms of the sea, and the comparison is apt. By constantly ingesting and excreting sediment, they turn over enormous quantities of material. On coral reefs, the nocturnal species Stichopus cf. monotuberculatus processes sediment at an average rate of about 7.8 grams per hour, with larger individuals moving even more.10Coral Reefs. Movement dynamics, sediment turnover and sheltering behaviours of the nocturnal coral reef sea cucumber, Stichopus cf. monotuberculatus Their fecal casts are organically richer and finer-grained than the surrounding sediment, indicating that they preferentially consume the nutrient-dense fraction.
This constant processing has chemical consequences for the reef. Sea cucumber digestion dissolves calcium carbonate, the mineral that coral skeletons are made of. The process involves a chain of reactions inside the gut: respiratory carbon dioxide lowers pH, digestive acids further drop it, and calcium carbonate dissolves in response, partially buffering the acidity.11Estuarine, Coastal and Shelf Science. Inorganic carbon turnover caused by digestion of carbonate sands and metabolic activity of holothurians In a healthy reef system, this dissolution is a normal part of the calcium carbonate cycle. But when sea cucumbers are overharvested, the consequences ripple outward. Research on the black sea cucumber Holothuria atra found that its grazing reduced the microbial load in reef sediment by roughly 75%, effectively keeping bacterial populations in check.12The ISME Journal. Sea cucumber grazing linked to enrichment of anaerobic microbial metabolisms in coral reef sediments Remove the grazers, and sediment microbial communities shift toward anaerobic metabolisms that can degrade reef health.
How Sea Cucumbers Defend Themselves
Given that sea cucumbers are soft-bodied, slow-moving, and nutritionally appealing, you might wonder how they survive at all. They have evolved some remarkably creative defenses. Certain species in the family Holothuriidae possess Cuvierian tubules, specialized organs that can be ejected from the body when the animal is disturbed. These white, sticky filaments are both extremely adhesive and strong enough to entangle and immobilize a would-be predator.13PubMed. Characterization of the adhesive from cuvierian tubules of the sea cucumber Holothuria forskali (Echinodermata, Holothuroidea)
Chemical defense adds another layer. Some species eject their internal organs (viscera) when stressed, and this turns out to be more than a dramatic distraction. Analysis of the viscera from stressed Apostichopus japonicus revealed triterpene saponins, a class of toxic compounds that showed acute toxicity in zebrafish embryo tests.14PubMed. Sea Cucumber Viscera Contains Novel Non-Holostane-Type Glycoside Toxins that Possess a Putative Chemical Defense Function These saponins are the same family of compounds that make some sea cucumber species mildly toxic to handle or process. For the culinary world, this is relevant because proper preparation, including thorough cleaning and the removal of internal organs, is partly about eliminating these naturally occurring toxins.
Feeding Farmed Sea Cucumbers
Aquaculture of sea cucumbers, particularly Apostichopus japonicus in China, has grown into a multi-billion-dollar industry. What to feed these animals at scale is an active area of research. In the wild, deposit-feeding species eat organic-rich sediment. Replicating that in ponds or tanks typically involves some combination of sea mud, dried seaweed powder, and supplementary ingredients.
One line of research has explored whether cheaper plant materials can substitute for seaweed, which is itself a valuable crop. Replacing up to about 22.5% of the seaweed in a standard diet with powdered corn leaf had no negative effects on growth, and the optimal inclusion was estimated at around 11%, with a recommended diet of 70% sea mud, about 19% seaweed, and 11% corn leaf.15Aquaculture. Substituting seaweed with corn leaf in diet of sea cucumber (Apostichopus japonicus): Effects on growth, feed conversion ratio and feed digestibility Adding benthic matter (essentially natural seafloor sediment with its resident microbes) to algae-based diets boosted protein efficiency and increased the concentration of omega-3 fatty acids like EPA and DHA in the animal’s tissues.16Aquaculture. Effects of different feed ingredients on growth, fatty acid profiles, lipid peroxidation and aminotransferases activities of sea cucumber Apostichopus japonicus (Selenka)
Carbohydrate levels matter too. Growth rate and feed efficiency in A. japonicus peaked at dietary carbohydrate levels around 48 to 49%, then declined at higher levels as glucose metabolism became impaired.17Aquaculture. Effects of dietary carbohydrate level on growth, biochemical composition and glucose metabolism of juvenile sea cucumber Apostichopus japonicus (Selenka) Too much carbohydrate led to increased fat deposition and signs of metabolic stress, similar in concept to what happens in many other animals overfed on starchy diets.
One quirk of farming A. japonicus is that these animals enter a dormant state called aestivation during summer, when water temperatures rise. Over roughly 100 days, they stop eating entirely, their intestines degenerate, and they lose substantial body mass.18Aquaculture. A potential feeding regulation strategy during aestivation: Relaxation of intestine mediated by pedal peptide/orcokinin-type neuropeptides in sea cucumber Apostichopus japonicus This is a serious constraint on production efficiency and one reason that farmers in northern China time their harvest and growing seasons carefully around this biological clock.
Sea Cucumbers as Aquaculture Cleanup Crew
One of the more promising developments in sea cucumber farming is integrating them into existing fish or shellfish operations, an approach called integrated multi-trophic aquaculture. The logic is straightforward: fish farms produce organic waste in the form of uneaten feed and feces, and sea cucumbers can eat that waste, converting pollution into a second valuable crop.
The suspension-feeding species Cucumaria frondosa absorbed over 70% of the organic material in particulates typical of its natural environment, and when exposed to higher-organic-content material like salmon feed and feces, its absorption efficiency rose above 80%.19Aquaculture. The absorption efficiency of the suspension-feeding sea cucumber, Cucumaria frondosa, and its potential as an extractive integrated multi-trophic aquaculture (IMTA) species In the Mediterranean, stable isotope and fatty acid analysis confirmed that the deposit-feeding species Holothuria poli placed near commercial fish cages was directly incorporating fish farm waste into its tissue.20PubMed. Stable isotope and fatty acid analysis reveal the ability of sea cucumbers to use fish farm waste in integrated multi-trophic aquaculture The fatty acid profiles were telling: sea cucumber tissue near the cages contained elevated levels of terrestrial plant fatty acids like oleic and linoleic acid, which are abundant in the plant-oil-based fish feeds but would never normally appear in a wild sea cucumber. Trials with gilthead seabream waste showed that sea cucumbers digested the waste material more efficiently than sea urchins, at rates potentially sufficient for productive growth on a diet of nothing but farm waste.21Aquaculture. Testing the digestibility of seabream wastes in three candidates for integrated multi-trophic aquaculture: Grey mullet, sea urchin and sea cucumber
This approach has environmental appeal, but it also raises a question for the consumer: if the sea cucumber you are eating was raised on fish farm waste, does that affect its quality or safety? The fatty acid data suggest the tissue composition does shift, which could be a selling point (more omega-3s from the fish feed) or a concern (terrestrial plant oils that would not occur naturally). Research in this area is still young, and regulatory frameworks for labeling or grading IMTA-raised sea cucumber products have not caught up.
Food Fraud and Species Mislabeling
Dried sea cucumber all looks roughly similar to the untrained eye: dark, wrinkled, and shrunken. This creates a ripe environment for fraud. A study using DNA mini-barcoding on twelve highly processed sea cucumber products found that over 83% were mislabeled, with cheaper species substituted for premium ones or blended together without disclosure.22Food Control. Authentication of sea cucumber products using NGS-based DNA mini-barcoding This was the first report to use next-generation sequencing to detect species fraud in heavily processed sea cucumber, and the scale of mislabeling was striking.
The problem extends beyond consumer deception into conservation. In 2023, Brazilian authorities seized dried sea cucumber specimens at SĂŁo Paulo’s international airport that were identified through DNA barcoding as two species harvested from Brazilian waters, where commercial sea cucumber fishing is not permitted.23PubMed Central. DNA-based identification uncovers the illegal trade of sea cucumbers from Brazil The case illustrated how the dried product can be moved across borders with little chance of visual identification, making molecular tools essential for enforcement. For buyers, the practical takeaway is that price and labeling are unreliable guides to what species you are actually getting, particularly for dried or powdered products purchased online or in unregulated markets.
Microplastics and Emerging Safety Concerns
Because sea cucumbers feed by processing large volumes of sediment or suspended particles, they are inevitably exposed to whatever contaminants are present in their environment. Microplastics have become a particular focus. A systematic review found that sea cucumbers, as both deposit and suspension feeders, are expected to ingest microplastics in their habitat, and researchers are increasingly documenting their occurrence in sea cucumber tissue.24PubMed. Microplastics occurrence in sea cucumbers and impacts on sea cucumbers & human health: A systematic review The health implications for both the animals and the humans eating them are still being mapped out, but the concern is real given how efficiently these animals concentrate material from their surroundings.
Heavy metals are another consideration, particularly for wild-caught specimens from polluted coastal areas. Sea cucumbers’ indiscriminate sediment ingestion means they can accumulate cadmium, lead, and arsenic if those metals are present in the seafloor. Farmed specimens, especially those raised in controlled environments with known sediment inputs, may have an advantage here, though the trade-off is the questions around feed composition described above. If you are buying sea cucumber regularly, sourcing from reputable suppliers who can identify the species and origin is the most practical way to reduce these risks.