Jellyfish are ancient animals — even older than the dinosaurs! These mesmerizing creatures have thrived for millions of years, proving that you don’t need a complex brain to be successful.
Florida’s waters are home to all sorts of marine life, and that includes a variety of jellyfish. Whether you’re swimming, boating, or just strolling along the beach, you’re likely to encounter these gelatinous invertebrates.
This article will give you the lowdown on common jellyfish of Florida, helping you identify them, understand potential dangers, and know what to do if you get stung. We’ll cover everything from identifying different species to essential first aid tips, so you can enjoy Florida’s beautiful coast with confidence.
Understanding Jellyfish: Biology and Behavior
To better appreciate (and maybe avoid!) the jellyfish of Florida, it’s helpful to know a bit about their biology and behavior.
Basic Jellyfish Biology
Jellyfish are invertebrates, meaning they don’t have a backbone. They’re soft-bodied creatures made up mostly of water, and they lack some of the organs we typically associate with animal life, like a brain or a heart. They’re classified as zooplankton, meaning they’re drifting animals that can’t swim against currents.
They eat plankton and small fish, catching their prey with their tentacles.
Jellyfish Life Cycle and Reproduction
The jellyfish life cycle is a bit complex, involving a polyp stage (a stationary, stalk-like form) and a medusa stage (the free-swimming, bell-shaped form we typically recognize). Some species of jellyfish also exhibit bioluminescence, meaning they can produce their own light.
Jellyfish Distribution and Seasonality in Florida
You can find jellyfish throughout Florida’s coastal waters. They tend to be more concentrated during the warmer months, from May to October, with their numbers peaking in August and September. Warmer seawater and an abundance of plankton can contribute to larger jellyfish populations.
Common Jellyfish Species in Florida
Florida’s coasts are home to many different types of jellyfish, some of which are harmless and some of which can deliver a painful sting. Here’s a rundown of some of the more common species you might encounter.
Non-Venomous Species
Moon Jellyfish (Aurelia aurita)
Moon jellies are common in Florida waters and are pretty easy to spot. They’re recognizable by their translucent, saucer-like bells and short tentacles. While they’re generally considered safe to touch, it’s still possible to experience some mild irritation if you come into contact with them. Moon jellies typically grow to be about 8 to 12 inches in diameter.
Venomous Species
Cannonball Jellyfish (Stomolophus meleagris)
Cannonball jellyfish are another common sight in Florida. These jellyfish are named for their round, firm bodies. While they do have stinging cells, their stings are usually mild and not considered dangerous to humans. Cannonball jellies are typically around 10 inches in diameter.
Atlantic Sea Nettle (Chrysaora quinquecirrha)
Sea nettles are known for their distinctive reddish-brown bells and long, trailing tentacles. These jellyfish can deliver a painful sting, so it’s best to avoid contact with them. Sea nettles typically range in size from 10 to 16 inches in diameter.
Box Jellyfish (Chiropsalmus quadrumanus)
Box jellyfish are among the most venomous creatures in the ocean, but they are rare in Florida. They have a cube-shaped bell and long, trailing tentacles that can deliver a potentially deadly sting. Encounters with box jellyfish should be avoided at all costs. They’re around 12 inches in diameter.
Portuguese Man-o’-War (Physalia physalis)
Although often mistaken for jellyfish, Portuguese man-o’-war are actually siphonophores, which are colonies of individual organisms working together. They’re easily identified by their gas-filled bladder, which floats on the surface of the water, and their long, venomous tentacles, which can extend for up to 30 to 100 feet. Man-o’-war stings can be extremely painful and even dangerous, so it’s best to steer clear of them.
By-the-Wind Sailor (Velella velella)
Like the Portuguese Man-o-War, By-the-Wind Sailors aren’t technically jellyfish, but hydrozoans. They’re smaller and less dangerous than Man-o-War, but they can still cause skin irritation. They’re usually smaller than 4 inches and have a small, clear “sail” that helps them move across the water’s surface.
Jellyfish Stings: Symptoms, Treatment, and Prevention
A jellyfish sting can range from a minor annoyance to a major medical event. Here’s what to do if you or someone near you gets stung.
Symptoms of Jellyfish Stings
Symptoms can vary in intensity. Most jellyfish stings cause immediate pain and a burning sensation, along with redness, swelling, and itching at the site of the sting. In severe cases, a sting can lead to nausea or difficulty breathing.
First Aid for Jellyfish Stings
If you’re stung by a jellyfish, here’s what you should do:
- Rinse the area with saltwater. Don’t use freshwater, as that can make the stinging worse.
- Apply a mild acid like vinegar, followed by warm water.
- Carefully remove any visible tentacles using tweezers or another flat object, like a credit card.
- Apply heat or cold packs to the affected area.
- Relieve itching with an over-the-counter insect bite remedy like Benadryl or cortisone cream.
Prevention of Jellyfish Stings
The best way to deal with a jellyfish sting is to avoid being stung in the first place. Here are some steps you can take to protect yourself:
- Pay attention to official warnings and signage at beaches.
- If the beach has lifeguards, look for purple flags, which mean that dangerous marine life has been spotted.
- When jellyfish are likely, wear protective gear like a wetsuit, rashguard, and gloves.
- If you see jellyfish washed up on the beach, that means there are likely more in the water. This is especially true if the wind is blowing onshore.
- Never touch a dead jellyfish. The stinging cells can still be active, even if the jellyfish is no longer alive.
- Divers, take note: Don’t touch your face with your diving gloves after you surface.
When to Seek Medical Attention
In some cases, a jellyfish sting requires medical treatment. Seek professional medical care if:
- Symptoms are severe, such as nausea or difficulty breathing, or if the sting affects an area larger than 19 square inches.
- The sting covers a large area of your body or is near your eyes or mouth.
- You’re showing signs of an allergic reaction.
Interesting facts and unique perspectives
Jellyfish in space
In 1991, the Space Shuttle Columbia carried out an experiment involving 2,478 jellyfish polyps. These tiny creatures multiplied in orbit, resulting in a population of roughly 60,000 jellyfish floating around in space!
Myths and trivia about jellyfish
One common myth is that urinating on a jellyfish sting will ease the pain. That’s not true, and may even make it worse. Instead, flush the area with vinegar.
Here’s a fun fact: Jellyfish are ancient creatures! They’ve been around for more than 500 million years, even before dinosaurs.
Watching luminous jellyfish in Florida
Some jellyfish species are bioluminescent, meaning they can produce their own light. Although I haven’t been able to confirm specific locations in Florida where you can reliably observe these glowing jellies, it’s worth checking with local marine centers or tour operators to see if they offer nighttime viewing opportunities.
The Bottom Line
Florida’s coastal waters are home to a fascinating array of jellyfish, from the relatively harmless moon jelly to the potentially dangerous Portuguese man-of-war. Knowing which jellyfish you’re likely to encounter and how dangerous they are is key to enjoying Florida’s beaches safely.
Taking precautions such as wearing protective clothing, avoiding jellyfish after storms, and heeding posted warnings can minimize your risk of getting stung. And remember, jellyfish play an important role in the marine ecosystem, so it’s vital to respect their space and avoid disturbing them.
By staying informed, being cautious, and respecting the environment, you can enjoy Florida’s beautiful beaches and coastal waters responsibly and safely.