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“ Thimble Jellyfish/sea lice ”

Vancouver, Canada
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“ Thimble Jellyfish/sea lice ”

bump- originally posted by Cunspin Feb 07, 2006,

Since May is an active season for 'sea lice' and I found this very helpful I thought I'd post again..

INFORMATION from--Universidad Nacional Autonoma De Mexico

What is the Thimble Jellyfish?

This marine animal is a small jellyfish resembling a thimble that measures about 1" in diameter and is conspicuosly mottled with dark brown markings. This Jellyfish, together with corals, seaanemones, hydeoids and hydras are included in a group of animals without skeletons named cnidarians. One characteristic of this important group is that they have numerous stinging cells called nematocystswhich act as microscopic syringes to inject toxins when touched.

Along the Mexican Caribbean coast dense aggregations of the THIMBLE JELLYFISH appear everyyear from late January to early June. The Jellyfish occur in 3 swimmming stages as juveniles or ephrae, as adults and as larvae or planulae. They are transported by winds and currents to other areas on the time scale of a few hours to a few days.


Accidental contact with this jellyfish causes a skinrash known as seabathers eruption.

This dermatites is characterized by the acute appearance of small itchy erythmas that may, in some cases, evolve into pustules. This eruption occures predominantly on body areas that are covered by the bathing suit or subjected to pressure or rubbing, such as armpits, neck, groinand inner thighs.In some cases the dermatites includes chills, fever nausea, headache and weakness, particularly in children. Symptoms don not appear untill hours (1 to 24) after leaving the water.Because of this , Seabathers eruption is sometimes confused with viral gastroenterites or varicella (chicken pox). The lesions usually persist from a few days to weeks, after wich they spontaneously heal.


Perons with histories of allergies should avoid swimming in waters infested with Thimble Jellyfish. Swimmers who must risk exposure should avoid the use of T'shirts as they trap the thimble Jellyfish between skin and clothing thus increasing the severity of the reaction. After exposure to seawater, swimmers SHOULD NOT SHOWER WITH FRESH WATER. Fresh water triggers the stinging cells. It is advisable to change out of bathing suit as soon as possible and apply vinegar wich neitralizes the nematocysts that cling to the skin but have not yet released their toxins. Bathing suits should be thouroghly washed with detergent as symptoms may recur if contaminated suits that were poorly washed are re-worn.

Is there Treatment?

When the lesions are minimal the application of creams and lotions to reduce the rash is recommended . The use of antihystamines is often helpful but should not be done without consulting a Physician. In severe cases topical and systemic steroids may be used but always under Medical supervision. IMORTANT,

DO NOT SCRATCH the affected areas because this can lead to skin infections.

Charleston, South...
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1. Re: “ Thimble Jellyfish/sea lice ”

Note these are VERY random. We have been to the area 20 times and only once had exposure to these. The important thing to note if you feel itching in your bathing suit area go to your room at once and remove your bathing suit. Don't shower with your suit on and don't use the suit again until it has been washed in HOT water and dried in a HOT dryter. After my daughter's eruption we ended up disgarding the suit. There are products that can used befor exposure such as safe sea


Saint James City...
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for San Pedro
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2. Re: “ Thimble Jellyfish/sea lice ”

I saw lots of thimble jelly fish along the beach last week here on Ambergris. As in hundreds of them all along the shore.

I haven't seen any since.

Christina Lake...
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3. Re: “ Thimble Jellyfish/sea lice ”

Take SeaSafe! You'll be fine and it also comes with SPF!

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4. Re: “ Thimble Jellyfish/sea lice ”

I thought they didnt venture as far as south as the Riviera Maya

Chicago, Illinois
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5. Re: “ Thimble Jellyfish/sea lice ”

I have only encountered them once myself so we avoided the ocean and I have seen the rash once (awful for the poor girl that had it). If you see them stay out of the ocean til they blow thru!

6. Re: “ Thimble Jellyfish/sea lice ”

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Removed on: 20 June 2013, 07:11