‘Tis the season for jelly! What to know about Florida's moon jellyfish

This news may sting: beachgoers will probably be sharing the water with a nearly invisible companion that could pack a punch.

Aurelia aurita, also known as moon jellyfish, are in season in the Atlantic Ocean, and the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) is reminding the public to stay vigilant. 

These critters are native to Florida, and are also common in ocean waters between 43 and 88 degrees Fahrenheit. Reports of jellyfish near Panama City Beach prompted officials to fly purple flags, which warn about dangerous marine life last week. 

Here’s what to look out for and how to do your best to avoid sparring with this salty sea creature. 

JOSEPH PREZIOSO/AFP via Getty Images

What do moon jellyfish look like?

According to the University of Maine’s Maine Sea Grant, this species of jellyfish is clear with four white or pinkish rings on its top. They can grow up to 15 3/4 inches in diameter, Florida State Parks says. 

They can also appear light pink or purple, the Key West Aquarium says.

How can I avoid getting stung?

“Always be mindful of your surroundings when entering or exiting the water,” Chantille Weber, UF/IFAS Extension Bay County coastal resources coordinator, said. “Wearing thin layers, such as an exposure suit like a rash guard, dive skin or wetsuit, helps minimize and prevent direct contact with tentacles while swimming or diving.”

What do I do if I'm stung?

Fortunately, though a moon jellyfish sting isn’t fun, they’re “minor” and “non-lethal,” UF/IFAS says.  

Still, you should seek immediate medical attention for “significant pain, spreading redness, difficulty breathing or signs of an allergic reaction,” the institute says.

Otherwise, you can take the following steps:

1. Rinse the affected area with saltwater to help loosen and release nematocysts (stinging cells) from the skin.
2. Rinse the affected area with vinegar to neutralize any remaining venom. Avoid using freshwater, as this can worsen the sting.
3. Use a credit card edge, stick or gloved hand to gently scrape off any visible tentacles. Avoid rubbing the area to prevent further venom release.
4. Apply hot water or a heat pack to the affected area to reduce pain. Hot water should be as hot as possible without scalding. If heat is not available, use a cold pack or ice in a dry plastic bag for temporary relief.

Fun facts

According to the Key West and South Carolina aquariums:

• Moon jellyfish are an important food source for other animals, including sea turtles
• The distinct clover shape seen through the bell is the gonads of this species
• They are actually considered plankton because their body is not strong enough to swim against currents