White Spot Disease - Fact Sheet

What is white spot disease?

White spot disease is an infectious disease of crustaceans. It is caused by the white spot syndrome virus, which belongs to the family Nimaviridae.

What species of crustaceans can be infected by white spot disease?

Each species of crustaceans may have several common names, but only one common name is listed.

Species susceptible to white spot disease that exist in the natural environment in Canada include:

• Cancer irroratus* (Atlantic rock crab*)
• Carcinus maenas* (green crab*)
• Homarus americanus* (American lobster*)

Species susceptible to white spot disease that do not occur in the natural environment in Canada include:

• Astacus leptodactylus (Turkish crayfish)
• Atergatis integerrimus* (red egg crab*)
• Calappa lophos (common box crab)
• Calappa philarigus* (spectacled box crab*)
• Callinectes sapidus (blue crab)
• Cancer pagurus (edible crab)
• Charybdis annulata (banded-leg swimming crab)
• Charybdis cruciata (crucifix crab)
• Charybdis feriatus (red flowery crab)
• Charybdis granulata portunid (crab)
• Charybdis hoplites (not applicable)
• Charybdis lucifera (box crab)
• Charybdis natator* (not applicable*)
• Cherax destructor (yabby)
• Cherax quadricarinatus* (Australian red claw crayfish*)
• Crangon crangon* (common shrimp*)
• Demania splendida* (not applicable*)
• Exopalaemon orientis (oriental prawn)
• Farfantepenaeus aztecus (brown shrimp)
• Farfantepenaeus duorarum (spotted pink shrimp)
• Fenneropenaeus chinensis (fleshy prawn)
• Fenneropenaeus indicus (white Indian prawn)
• Fenneropenaeus merguiensis (banana prawn)
• Fenneropenaeus penicillatus redtail (prawn)
• Gelasimus marionis nitidus (Indian fiddler crab)
• Grapsus albolineatus* (mottled sally-light-foot*)
• Halimede ochtodes* (not applicable*)
• Homarus gammarus (European lobster)
• Liagore rubronaculata* (not applicable*)
• Liocarcinus depurator* (not applicable*)
• Liocarcinus puber (velvet swimming crab)
• Lithodes maja* (Norway king crab*)
• Litopenaeus setiferus (northern white shrimp)
• Litopenaeus stylirostris* (blue shrimp*)
• Litopenaeus vannamei (whiteleg shrimp)
• Macrobrachium idella (sunset shrimp)
• Macrobrachium lamerrae (Kuncho river prawn)
• Macrobrachium rosenbergii (giant river prawn)
• Macrophthalmus sulcatus (ocypodid)
• Marsupenaeus japonicus (kuruma prawn)
• Matuta miersi* (not applicable*)
• Matuta planipes (flower moon crab)
• Menippe rumphii*(not applicable*)
• Metapenaeus dobsoni(kadal shrimp)
• Metapenaeus elegans (fine shrimp)
• Metapenaeus ensis (greasyback shrimp)
• Metapenaeus lysianassa (bird shrimp)
• Metapograpsus messor (mangrove rock crab)
• Metapenaeus monoceros (speckled prawn)
• Orconectes limosus* (camber crayfish*)
• Pacifastacus leniusculus (signal crayfish)
• Palaemon adspersus (Baltic prawn)
• Panulirus homarus* (scalloped spiny lobster*)
• Panulirus longipes (long-legged spiny lobster)
• Panulirus ornatus (ornate spiny lobster)
• Panulirus penicillatus (pronghorn spiny lobster)
• Panulirus polyphagus* (mud spiny lobster*)
• Panulirus versicolor (painted spiny lobster)
• Paradorippe granulata* (not applicable*)
• Paraperaeopsis stylifera (karikkadi shrimp)
• Parthenope prensor* (not applicable*)
• Penaeus monodon (giant tiger prawn)
• Penaeus semisulcatus (green tiger prawn)
• Podophthalmus vigil* (long-eyed swimming crab*)
• Portunus pelagicus (sand crab)
• Portunus sanguinolentus* (three spot swimming crab*)
• Procambarus clarkii (red swamp crayfish)
• Pseudograspus intermedius (grapsid crab)
• Scylla serrata (giant mud crab)
• Scylla tranquebarica* (not applicable*)
• Scyllarus arctus (small European locust lobster)
• Solenocera indica (coastal mud shrimp)
• Squilla mantis (mantis squillid)
• Thalamita danae* (not applicable*)
• Trachysalambria curvirostris (southern rough shrimp)
• Uca pugilator* (Atlantic sand fiddler*)

Note: Species identified with an asterisk have not been confirmed as susceptible to white spot disease.

Is white spot syndrome virus a risk to human health?

No. The causal agent of white spot disease is not a risk to human health.

What are the signs of white spot disease?

White spot disease causes death in juvenile and adult crustaceans. Infected animals die within 3 to 10 days of the appearance of the disease.

Affected crustaceans may exhibit any of the following signs:

• behaviour
  • decreased appetite
  • gather near the surface and edges of the rearing units
• appearance
  • white spots in the shell
  • appear darkened and red or pink in colour
  • covered with debris (not preening to keep clean)
  • gut appears white in colour
  • shell may be loose

Is white spot disease found in Canada?

No. White spot syndrome virus is not currently found in Canada.

How is white spot disease spread?

White spot disease is spread between crustaceans by

• cannibalism, and
• water contaminated with the virus.

People can spread the disease by moving any of the following:

• infected live or dead crustaceans,
• contaminated equipment, or
• contaminated water.

How is white spot disease diagnosed?

Diagnosing white spot disease requires laboratory testing. Not all infected crustaceans will show signs of disease.

How is white spot disease treated?

There are no treatment options currently available for white spot disease.

What measures can be taken to prevent the introduction and spread of white spot disease?

If you frequently handle or work with crustaceans, be aware of the signs of white spot disease.

Do not import infected crustaceans into Canada.

• An import permit is required from the Canadian Food Inspection Agency (CFIA) for certain species of crustaceans.
• People bringing crustaceans into Canada should check other federal, provincial, and/or territorial requirements before they import crustaceans or enter into Canada with crustaceans.

Do not introduce live crustaceans from another country or province into the natural waters of Canada.

• People releasing crustaceans into the natural waters or into rearing facilities within Canada should check if federal or provincial and/or territorial permits are required.

Shells removed from crustaceans should be disposed of in your municipal garbage.

Do not use crustaceans that were bought in a grocery store as bait for catching finfish or other aquatic animals. 

The CFIA recommends that you do not visit Canadian aquaculture sites, zoos or aquariums for 14 days if you have travelled to another country, and

• visited an aquaculture site, or
• had contact with wild crustaceans.

Wash and disinfect the footwear you wore to the site or when you had contact with wild crustaceans. Also, wash your clothing thoroughly and dry it at a high temperature.

What is done to protect Canadian aquatic animals from white spot disease?

White spot disease is a reportable disease in Canada. This means that anyone who owns or works with aquatic animals, who knows of or suspects white spot disease in the animals that they own or work with, is required by law to notify the CFIA.

If white spot disease is found in Canada, the CFIA would control its spread by implementing disease response activities. These may include

• controlling the movements of infected animals
• humanely destroying infected animals
• cleaning and disinfecting

The control measures chosen would depend on the situation. 

What do I do if I think crustaceans that I am raising or keeping have white spot disease?

If you suspect a crustacean that you are raising or keeping may have white spot disease, you are required under the Health of Animals Act to immediately notify the CFIA.

How do I get more information

For more information about reportable diseases, visit the Aquatic Animal Health page, contact your local CFIA Animal Health Office, or your CFIA Area office:

• Atlantic: 506-777-3939
• Quebec: 514-283-8888
• Ontario: 226-217-8555
• West: 587-230-2200