Types of Jellyfish in Florida
Florida's coastal waters host several jellyfish species, including moon jellyfish, Atlantic sea nettle, cannonball jellyfish, and the occasional Portuguese man o' war. This guide helps you identify the most common types by shape, color, and sting severity, so you know what to expect at the beach.
Florida's coastal waters host several jellyfish species, including moon jellyfish, Atlantic sea nettle, cannonball jellyfish, and the occasional Portuguese man o' war. This guide helps you identify the most common types by shape, color, and sting severity, so you know what to expect at the beach.
1. What are the most common jellyfish in Florida?
The species you are most likely to encounter are the moon jellyfish (Aurelia aurita), Atlantic sea nettle (Chrysaora quinquecirrha), cannonball jellyfish (Stomolophus meleagris), and the Portuguese man o' war (Physalia physalis). Moon jellies are translucent saucers with four horseshoe-shaped gonads, often seen in large numbers. Atlantic sea nettles have a bell with reddish-brown stripes and long tentacles. Cannonballs are dome-shaped with a brownish fringe and are frequently found near inlets. Portuguese man o' wars are not true jellyfish but have a distinctive blue floating sail.
2. How can you tell these jellyfish apart?
Focus on the bell shape, color, and tentacle arrangement. Moon jellies are clear or slightly blue with a flat bell and short, hair-like tentacles. Sea nettles have a bell with reddish radial lines and long, stinging tentacles. Cannonballs are firm, rounded, and often have a brown or yellow tint; their tentacles are short and in a fringe. Portuguese man o' wars have a gas-filled bladder that floats above the water, trailing long tentacles underneath. Sting severity also helps: moon jellies cause mild irritation, sea nettles a moderate sting, cannonballs are harmless to humans, and man o' wars deliver a very painful sting.
3. Where and when are each type most likely to be seen?
Moon jellies appear year-round but peak in spring and summer, often washing up on Atlantic and Gulf beaches after strong winds. Sea nettles are common in summer along the Atlantic coast, especially in estuaries like the Indian River Lagoon. Cannonball jellyfish swarm in late spring to early fall near inlets and brackish rivers, and are especially abundant in the northern Gulf. Portuguese man o' wars are rare but arrive with onshore winds in winter and spring, mostly on the Atlantic side. The best odds for sightings are after storms or during high tides.
4. Which other jellyfish might you see in Florida?
Besides the main four, you may encounter the mushroom jelly (Rhopilema verrilli), which has a bell with cauliflower-like projections and no tentacles, and the upside-down jellyfish (Cassiopea), which lies on the seafloor in mangrove areas. Both are mild stingers. The mauve stinger (Pelagia noctiluca) is a small, purple jelly with a potent sting that occasionally appears offshore after Gulf Stream currents. These are less common but worth knowing if you plan to dive or snorkel.
See ourstate animal guidefor the next step.
5. What should you do if you get stung?
For moon jellies and sea nettles, rinse the sting with vinegar (not fresh water) to neutralize nematocysts, then remove tentacles with tweezers or a credit card, and apply hot water or ice. For cannonballs, no treatment is usually needed. Portuguese man o' war stings require immediate medical attention; first remove tentacles carefully and rinse with salt water, then seek help. Avoid rubbing or using urine, as that can make it worse. Knowing which species stung helps decide care.
6. Where can I find jellyfish identification gear and gifts?
Once you learn to identify Florida's jellyfish, you might want to show off your knowledge with some fun gear. Check out these options from Easy Street Markets:
### Jellyfish Men's T-Shirt
A durable tee with a bold jellyfish graphic perfect for beach days or casual wear.Check Price and Availability
### 5Aup Scientifically Accurate Coral Reef Mug Gifts 11oz [![5Aup Scientifically Accurate Coral Reef Mug Gifts...