Holothuroidea belongs to echinoderms. They are like ocean urchins and starfish. Furthermore, there are around 1,250 identified species, and a large number of these creatures are to be sure molded like delicate bodied cucumbers.

All ocean cucumbers are sea inhabitants. However, some live in the deep sea and others occupy the shallows. Moreover, they live on or close to the sea floor and some of the time partly buried underneath it.

Furthermore, few of these sea cucumbers are around 20 cm long. Grown-ups of some small species may not surpass a centimeter, while one huge species can achieve lengths of 5 m (Synapta maculata). A few species of this types can swim.


Although, there are even forms that live their whole lives as plankton, skimming with the sea streams. Commercially, Holothuroidea is essential in two principal ways. Initially, a few species create poisons that are important to pharmaceutical firms trying to learn their medical importance.

A few compounds disconnected to date exhibit antimicrobial action. Although, some of them acts as anticoagulants and anti-inflammatory agents.

Secondly, as a gourmet food thing in the Orient, they frame the foundation of a multimillion-dollar industry that procedures the body wall available to be purchased as trepan or beche-de-mer.

Moreover, the high estimation of a few animal groups, the comfort with which such shallow-water forms can be gathered and their unstable age structures all add to over-misuse and fall of the fisheries in a few areas.

Many fishermen in the Pacific islands utilize the poisons, some of which go about as respiratory inhibitors, to attract octopus and fish from cracks with the goal that they might be more effortlessly skewered. Moreover, the sticky Cuvierian tubules are put over bleeding injuries as a Band-Aid.


NameSea cucumber
Scientific NameHolothuroidea
Synonymsbrown sea cucumber,
Holothuria tubulosa (Gmelin, 1791),
Holothuria maxima (Delle Chiaje, 1823),
Holothuria tremula (Linnaeus, 1767),
tubular sea cucumber,
Holothuria petagnae (Delle Chiaje, 1824)

Vernacular names of Holothuroidea

English: Holothurian

Dutch: Zeekomkommers

Finnish: Merimakkarat

French: cocombres de mer

Japanese: ナマコ綱

Portuguese: holotúria

Swedish: Sjögurkor


History about the sea cucumbers is given below:

Origin of  Holothuroidea

Their origin is found to be from all oceans of the world.

Fossil records

With respect to most delicate bodied creatures, holothuroids have a poor fossil record. Distributed records exist of body fossils for around 19 species. However at any rate that many body-fossil species were placed undescribed on historical center racks.

Most old holothuroids are identified from fossils of isolated ossicles. Furthermore, this confuses the scientific classification to some degree since ossicles can vary even within an individual relying upon habitat, geology, and age. How at that point does one recognize a single animal type?

Thus, most fossil holothuroids have been portrayed as paraspecies based on matchless ossicles kinds. Whole or confined components of the calcareous ring are likewise known. However, less work has been done on these conceivably educational and informative structures.

The uncommonness of holothuroids fossils to some extent might be because of an absence of gathering effort. Since the tiny ossicles require extraordinary gathering techniques.

Besides this, there are a couple of experts working in the group. Also, isolated ring components may some of the time be mistaken for the strong plates of different echinoderms.

Holothuroids presumably developed by at least the Lower Silurian, most a little-known gathering of wiped out Paleozoic echinoderms known as ophiocistioids. Although, the most ancient revealed body fossil from the Lower Devonian, while the eldest undoubted ossicle is from the Upper Silurian.


Plate ossicles are recognized from the Ordovician, yet their individuality as holothuroid is unverifiable in light of the fact that they look like the plates of many other echinoderms.

All things considered, plate ossicles ascribable to holothuroids are outstanding and, when joined with the phylogenetic proof, propose that few gatherings of antiquated plated frames existed that are just remotely related with living plated dactylochirotes and dendrochirotes.

On the other hand, these living structures have held their antiquated defensive layer and Holothuroidea has had a long and rehashed history of losing a plate morphology.

Distinctive Features

There are many distinctive features of sea cucumbers which are given below:

Geo-distribution of  Holothuroidea

Holothuroidea is seen in oceans all over the world.

Biogeographic Areas:  Atlantic Ocean, Indian Ocean, Pacific Ocean, Mediterranean Sea


Despite the fact that they change in shading, most holothurians are dark, olive green or brown. Ranging from three cm to one m long, the biggest ocean cucumbers may have a width of 24 cm.

Holothurians usually look stretched and worm-like. However, it holds the pentaradial regularity characteristics like the Echinodermata. Some might be circular in body shape.

The anus and mouth are situated on inverse poles, and five lines of tube feet keep running from the mouth to the other end along the tube-shaped body. Ten to thirty spreading tentacles are around the mouth. The arms are quite of the water vascular system.

Furthermore, the water vascular framework, found in all echinoderms, suits the prolonged body of the holothurians. Moreover, coelomic liquid, as opposed to ocean water, circulates from the water vascular system. Although, the ring trench around the gut has 1-50 Polian vesicles.

They may work for hydraulic regulation. Therefore, every spiral trench has lines of the ampulla. Podia, which are the outer bit of the tube feet, might be lost, suckered, or diminished.

Podia are more arbitrarily scattered along the body than in different echinoderms. Furthermore, the foregut, throat and radial channel of the water vascular framework are upheld by calcareous plates.

Holothurians fundamentally situate themselves to have the trivium on the substrate which is ventral side and the bivium looking up which is dorsal side.

In the Holothuroidea, the perforated plate is unattached to the coelom and is inward, lying underneath the pharynx in the CD-interambulacral position. Moreover, a small stone trench pursues the madreporite.

While bolster in many echinoderms is from the skeletal structure, in ocean cucumbers, thick sheets of body wall muscles offer help. Tiny sclerietes or ossicles are on the dermal layer and are utilized in ordered distinguishing proof.

Respiratory trees, which branch out close to the rectum of the creature are utilized for gas trade as water is pumped through the other end (anus). Furthermore, the respiratory trees are a portion of the organs that are ousted once in a while by the ocean cucumber.

Other features:  Heterothermic, ectothermic, radial symmetry, bilateral symmetry


The environment of Holothuria fuscogilva was surveyed in three natural surroundings in the Republic of Maldives: marine grass beds, lagoon floor, and island holes.

Sea cucumbers are found in all oceans of the world.

Food Habits

Ocean cucumbers feed on small particles like (algae) green growth, minute sea creatures, or waste materials, which they assemble in with 8 to 30 tube feet that resemble arms encompassing their mouths. The creatures separate these particles into considerably little pieces, which then become food for microbes.

Sea cucumber

Besides this, they reuse them once again into the sea environment. Nightcrawlers or earthworms play out a comparable function in earthbound environments.

As deposit feeders, holothurians trap particles and tiny fish on their arms which are fully covered with mucus. The arms are pushed into the mouth to swallow food. Besides this, the secretory cells from papillae of the gland cells and tentacles of the foregut discharge mucus.

Sea cucumbers are also enjoyed by people, particularly in Asia, and a few species are cultivated as delicacies.


Sea cucumbers are normal in shallow water zones to deep sea bottoms. Besides this, most are benthic and some are pelagic.

  • Marine Biomes: coastal
  • Habitat Areas: marine or saltwater
  • Other Habitat Features: littoral or intertidal

Behavior of Holothuroidea 

Whenever sea cucumbers are threatened, some of them release sticky strings to trap their enemies. Besides this, others can ruin their very own bodies as a protection system.

They fiercely get their muscles and discard a portion of their inner organs out of their anus. The missing body parts are immediately recovered and regenerated.


Breeding happens generally from the month of June to August and is expert by shedding sperm and eggs into the water where a process of fertilization happens.

During this shedding period, sea cucumbers obtain a “cobra-like” posture, with the front end lifted off the base. Besides this, the fertilized eggs form into hatchlings which may spend at least 70 days as microscopic fish suspended in the water before settling on the base and changing into a baby, young sea cucumbers.

Young ones are extremely secretive and they hide away in ocean weed, under stones, and in gaps. Development is believed to be slow, it requires at least four to five years for the grown-up size of 0. 5 kg to be touched. Their life expectancy might be over eight years.

Growth Life Cycle: Metamorphosis


Ocean cucumbers can breed asexually or sexually. Furthermore, sexual reproduction is more normal in sea cucumbers, however, the procedure is not very personal. The creatures discharge the two eggs and sperm into the water and the fertilization happens when they meet.

There must be numerous individuals in a sea cucumber populace for this regenerative technique to be fruitful. To be sure, numerous parts of the deep sea have expansive groups of these antiquated creatures, grazing on the tiny bounty of sea waters.

Key Reproductive Features:  dioecious /gonochoristic/ gonochoric / (genders separate), sexual fertilization (Internal, External), simultaneous hermaphrodite, oviparous, ovoviviparous

Parental Roles: pre-fertilization (Provisioning) and pre-hatching/birth (Caring: Female, Provisioning: Female)

Communication & Reception

The non-centralized sensory system of echinoderms enables them to detect their environment and condition from all sides. Furthermore, Holothurians have a nerve ring close to the base of the arms. The podia are touch-sensitive. Grown-up pheromones may attract hatchlings, which tend to settle nearby conspecific grown-ups.

  • Observation Channels: tactile; compound
  • Communication Channels: chemical
  • Other Communication Modes: pheromones


The average size of sea cucumbers is 0.75 into 6.5 ft.


Majority of species life from 5-10 years.

Health benefits

There are many health benefits of sea cucumbers:


Some animal-based study shows that sea cucumber may help retain cholesterol in check.

Gum Health

Furthermore, usage of a toothpaste having ocean cucumber extract might be useful to individuals with gum infections.


Persons with seafood allergies should evade the use of sea cucumber.

There’s also some worry that taking sea cucumber in combination with blood-thinning medications may have damaging effects.


Some of the initial researches show that certain compounds found in Holothuroidea may have cancer-fighting properties.

Medicinal Uses

In other medicine, Holothuroidea is advertised as a natural cure for the following fitness problems:

  • The common cold
  • Tendonitis
  • Erectile dysfunction
  • Constipation
  • Gum disease
  • Fatigue
  • High blood pressure
  • Osteoarthritis
  • High cholesterol

Holothuroidea is also believed to slow up the aging process and it also decreases inflammation. In addition, some supporters recommend that sea cucumber can help combat cancer.


Known Hazards

Ocean cucumbers, especially eggs and youthful hatchlings, are prey for fish and other marine creatures.

Similar Species

Fun Facts

There are many fun facts of sea cucumbers, they are given below:

Sea cucumber facts

Although, these fun facts are quite interesting yet there are some dangers as well.




Aymen Nizam

Aymen Nizam

I am IT (Graduate) from Bahria University Islamabad currently writing blogs on animals and plants, I am a content writer by profession and passionate about writing all information about living things. TapeDaily has provided me a chance to share my expertise with you.

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