Jellyfish are members of the Cnidaria family and have the characteristic umbrella or bell appearance. Their tentacles contain specialized stinging barbs, which pierce the skin and inject venom. There are four classes of jellyfish worldwide which include the Scyphozoa, Hydrozoa, Cubozoa and Anthozoa.
Is it toxic?
The most toxic are the box jellies (Cubozoa class), which inhabit tropical waters (they do not inhabit the coastal waters of Canada).
Jellyfish on the Canadian west and east coasts are:
- Scyphozoa: Lion's mane jellyfish (Cyanea capillata), moon jelly (Aurelia species), fried egg jelly (Phacellophora camtschatica).
- Hydrozoa: water jelly (Aequorea aequorea).
The lion's mane has a purple-red color and resembles a mane of hair floating in the water. Tentacles can be up to 30 meters long. It may cause an unpleasant sting, which lasts for several hours.
The moon and water jellies are translucent and the fried egg jelly has a yellowish translucent appearance; they have a very mild sting.
Health Effects (from jellyfish in Canadian coastal waters):Eye:
A sting directly to the eye may cause severe pain, tearing, redness, swelling of eyelids and potential injury to the cornea.Skin:
Immediate pain and stinging may last several hours. Small raised blanched bumps or welts develop and the area may become reddened. Linear or whip-like marks from contact with the tentacles are common.What to do (for jellyfish stings in Canadian coastal waters):Eyes:
Rinse eyes with a gentle stream of salt water
(not fresh water) for 15 minutes by any of the following methods:
- Pour a gentle stream of salt water from a jug or clean teapot over the eye from the inside corner by the nose, across the eye, flowing out towards the ear.
- Submerge eye in a container of salt water. Have patient open and close eye.
- Young children may be wrapped like a mummy in a towel with arms at side and held over the sink or tub or laid on counter during flushing.
If you have a sting directly to the eye, flush eye first and then go to an Emergency department for an ocular exam and assessment. If you have any questions or concerns, contact the Poison Control Centre.
- Flush area with a gentle stream of seawater.
- Do not use vinegar for stings from jellyfish in Canadian coastal waters. It may worsen the sting.
- Do not urinate on the sting area or flush with fresh water or alcohol, as this may cause firing of stingers.
- After flushing area, remove any remaining tentacles by scraping with a plastic card or dull edge of a knife.
- For jellyfish stings from outside of Canadian coastal waters, contact the Poison Control Centre.
If symptoms persist after the above first aid measures or you have any questions or concerns, contact the Poison Control Centre.
How can I prevent exposure?
Do not touch jellyfish even if they are lying on the beach.
Need more information:
Call the Poison Control Centre.
© 2010 BC Drug and Poison Information Centre