Tube rot (bacterial necrosis of body walls)
Tube rot is a serious bacterial disease affecting sea cucumbers, also known as holothurians. This marine animal, related to sea urchins and starfish, is highly valued in aquaculture, particularly in Asia, for its dried flesh. The disease ca...
What is it?
Tube rot is a serious bacterial disease affecting sea cucumbers, also known as holothurians. This marine animal, related to sea urchins and starfish, is highly valued in aquaculture, particularly in Asia, for its dried flesh.
The disease causes progressive destruction of the body wall—the thick "skin" that envelops the animal and gives it its tubular shape. It often progresses very rapidly and can lead to death within days.
It represents a major economic problem in intensive sea cucumber farming operations, where it can wipe out a large portion of a tank in a short time.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Related signs — each one links to its page:
Early signs are often subtle: the animal becomes soft, less active, and feeds less.
Small spots or discolored areas appear on the body wall, which rapidly develop into ulcers—open wounds that do not heal.
The body wall softens, tears, or breaks down in places, sometimes exposing internal organs.
The animal may expel part of its internal organs (evisceration), a natural defense mechanism in sea cucumbers that, when associated with this disease, worsens its condition.
In advanced forms, the entire body partially liquefies, which is how the disease earned its name "rot." Death typically occurs within days once symptoms are well established.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
The disease is associated with opportunistic bacteria, notably certain species of the genus Vibrio, which take advantage of an animal's weakened state or an injury to invade the body wall.
These bacteria naturally occur in seawater and become disease-causing when farming conditions promote their growth or weaken the sea cucumber's defenses.
High stocking density in rearing tanks favors rapid disease spread. Poor water quality, particularly water laden with organic matter or inadequately renewed, increases the risk. Sudden changes in temperature or salinity, along with injuries during animal handling, weaken the body wall and facilitate bacterial entry. Chronic stress, related to transport or unsuitable rearing conditions, also weakens the sea cucumber's natural defenses.
Transmission
Transmission occurs mainly through water contaminated with bacteria, but also through direct contact between animals in an overcrowded tank, and through contaminated farming equipment.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
Diagnosis relies on observation of characteristic lesions by a veterinarian specializing in aquatic animals or a pathologist specializing in aquaculture. Samples can be taken to identify the causative bacterium through bacterial culture or laboratory analysis. The rapid progression of the disease often makes early diagnosis difficult, underscoring the importance of careful monitoring of rearing tanks.
Treatment
Treatment, when feasible, rests on immediate improvement of rearing conditions: water renewal, reduction of stocking density, isolation of affected animals. Antibacterial treatments suited to aquaculture may be used under professional supervision, but their effectiveness remains limited once the disease is well established. Disinfection of the rearing environment is essential to prevent spread to other animals.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Prevention rests primarily on good farm management: maintaining reasonable stocking density in tanks, ensuring adequate water renewal, and regularly monitoring water quality. It is advisable to avoid unnecessary stress during handling or transport of animals, and to remove sick individuals quickly to limit spread. Regular disinfection of equipment and tanks, as well as quarantine of newly arrived animals before introduction into a healthy tank, are important measures.
Possible complications
The disease can result in significant and rapid mortality within a tank, with substantial economic losses for farmers. Evisceration associated with body wall necrosis greatly reduces the animal's chances of survival.
When to see a veterinarian
Appearance of unusual discolored patches or areas on the body wall of animals. Softening, ulceration, or visible tearing of the skin in one or more individuals. General decline in activity or appetite in a tank. Unexplained or grouped mortality in sea cucumber farming.
Prognosis
The prognosis is guarded to poor once signs are well established, with the disease potentially leading to death within several days.
Early detection and rapid improvement of husbandry conditions may sometimes make it possible to limit spread and save part of the stock.
Frequently asked questions
Is sea cucumber rot contagious between sea cucumbers?
Yes, it spreads easily in the water of a pond, especially if there are many animals in close contact.
Can a sick sea cucumber be treated?
Treatment is possible at an early stage, but the disease's often rapid progression makes cure difficult once lesions are well developed.
Does this disease pose a risk to humans?
No, it is not known to transmit to humans, but good hygiene remains recommended when handling sick animals.
How to prevent this disease in a farm?
By maintaining good quality water, a reasonable animal density, and quickly isolating any individual showing suspicious signs.
References
FAO — Organisation des Nations unies pour l'alimentation et l'agriculture
WOAH — Organisation mondiale de la santé animale (ex-OIE)
Content reviewed by the TunisieVet editorial team · Updated 01 September 2026
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