6 Types of Jellyfishes in New York
New York's coastal waters host several jellyfish species, with lion's mane, moon jelly, and sea nettle being the most common. You'll spot them from late spring through fall near Long Island beaches and the Hudson River estuary. Start with moon jellies for easy identification.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 7, 2026.
- 5
- species recorded
- April, May, July
- peak months
Verified species, source iNaturalist
6 types of jellyfishes recorded in New York
6 jellyfish species have a verified observation record in New York across true jellyfish (class Scyphozoa), each with at least 10 confirmed sightings. The full list, ranked by how often each is recorded, is below.
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Plus 4 more recorded only rarely (fewer than 10 verified sightings). Counts from verified iNaturalist observations. Photos by iNaturalist observers, reused under the licence each observer chose.
Real sighting data, source iNaturalist
710 verified observations on iNaturalist of jellyfish have been recorded in New York, most often in April, May, July.
New York's coastal waters host several jellyfish species, with lion's mane, moon jelly, and sea nettle being the most common. You'll spot them from late spring through fall near Long Island beaches and the Hudson River estuary. Start with moon jellies for easy identification.
What are the most common jellyfish in New York?
The three you'll run into most often are the lion's mane jellyfish (*Cyanea capillata*), the moon jelly (*Aurelia aurita*), and the sea nettle (*Chrysaora quinquecirrha*). I remember my first lion's mane washing up on Jones Beach – it was huge, with a reddish-brown bell and long, trailing tentacles. Moon jellies are translucent and easy to spot near the surface, while sea nettles show up in bays and estuaries with a pinkish tint. For a broader look at jellyfish biology, check out ourjellyfish overview.
How can you tell a lion's mane jellyfish apart from others?
Size and color are your best clues. Lion's mane jellyfish can have a bell up to 2 feet across (sometimes larger) and a mass of fine, hair-like tentacles that give it that mane look. The bell is usually reddish-brown or yellowish. In contrast, moon jellies are smaller (6-10 inches) and clear with four horseshoe-shaped organs. Sea nettles have a bell about 6-8 inches, with a whitish or pinkish color and long, thin tentacles. If you're near Long Island Sound in summer, you're most likely to see lion's mane. For more on New York's coastal wildlife, visit ourNew York wildlife page.
Where and when do you find moon jellyfish in New York?
Moon jellies are the most predictable. They appear in calm, warm waters like the south shore bays (Great South Bay, Shinnecock Bay) from June to September. They drift near the surface, often in groups. I've had the best luck at Comsewogue State Park in August, where they cluster around jetties. They're harmless to humans, so they're perfect for close-up observation. To see a map of typical jellyfish sightings, check ourjellyfish types guide for New York.
Are sea nettles dangerous in New York waters?
Sea nettles deliver a painful sting, but they're not life-threatening. They're common in the Hudson River estuary and the eastern bays of Long Island from July through September. The sting feels like a sharp burn and leaves a red welt. I've been tagged by one while wading at West Meadow Beach – it's unpleasant, but a vinegar rinse calms it down. If you're swimming, look for their transparent bell with reddish tentacles. Nettle numbers peak in late August.
See ourstate animal guidefor the next step.
What other less common jellyfish might you see?
Occasionally you'll spot the comb jelly (a ctenophore, not a true jellyfish) or the Portuguese man o' war (a siphonophore) if currents bring them up from the south. I saw a man o' war washed up at Rockaway Beach after a storm in 2022 – it's rare, but memorable. Also keep an eye out for the harmless blue button jellyfish (*Porpita porpita*) in the summer. For a full list, see ourNew York jellyfish identification page.
What gear helps you identify jellyfish on the go?
Once you've started spotting jellies, a quick reference can help. I keep a **Jellyfish Species Chart T-Shirt** handy – it's printed with the main types and their features, so I can ID them right on the beach.
Jellyfish Species Chart T-Shirt
This lightweight tee shows clear illustrations of lion's mane, moon jelly, sea nettle, and more. It's great for learning and teaching others.Check Price and Availability
Jellyfish Men's T-Shirt
A classic tee featuring a stylized jellyfish design. It's comfortable for a day of beachcombing and a conversation starter.Check Price and Availability
5Aup Scientifically Accurate Coral Reef Mug
This 11oz mug shows accurate reef life including jellyfish. Perfect for your morning coffee while planning your next spotting trip.Check Price and Availability
For more wildlife-themed gear, browse ourwildlife tote bags.
Do you get jellyfish in Lake Ontario?
Yes, freshwater jellyfish (*Craspedacusta sowerbii*) have been reported in Lake Erie and Lake Ontario, but they're rare and tiny (about the size of a penny). They appear in warm, still water in late summer. Don't expect to see them on a typical beach day – they're more common in inland ponds. For New York marine jellyfish, stick to the coast.
What should you do if you get stung by a jellyfish in New York?
For common stings from moon jellies or sea nettles, rinse with vinegar to neutralize the stingers. Do not use fresh water, which can trigger more nematocysts. Remove any tentacles with a gloved hand or tweezers. If pain persists or you have an allergic reaction, seek medical help. Always check local beach advisories – some beaches post flags when jellyfish are abundant.
See ourtour planning ideasfor the next step.
Frequently asked questions
What are the most common jellyfish in New York?+
The three you'll run into most often are the lion's mane jellyfish (*Cyanea capillata*), the moon jelly (*Aurelia aurita*), and the sea nettle (*Chrysaora quinquecirrha*). I remember my first lion's mane washing up on Jones Beach – it was huge, with a reddish-brown bell and long, trailing tentacles. Moon jellies are translucent and easy to spot near the surface, while sea nettles show up in bays and estuaries with a pinkish tint. For a broader look at jellyfish biology, check out ourjellyfish overview.
How can you tell a lion's mane jellyfish apart from others?+
Size and color are your best clues. Lion's mane jellyfish can have a bell up to 2 feet across (sometimes larger) and a mass of fine, hair-like tentacles that give it that mane look. The bell is usually reddish-brown or yellowish. In contrast, moon jellies are smaller (6-10 inches) and clear with four horseshoe-shaped organs. Sea nettles have a bell about 6-8 inches, with a whitish or pinkish color and long, thin tentacles. If you're near Long Island Sound in summer, you're most likely to see lion's mane. For more on New York's coastal wildlife, visit ourNew York wildlife page.
Where and when do you find moon jellyfish in New York?+
Moon jellies are the most predictable. They appear in calm, warm waters like the south shore bays (Great South Bay, Shinnecock Bay) from June to September. They drift near the surface, often in groups. I've had the best luck at Comsewogue State Park in August, where they cluster around jetties. They're harmless to humans, so they're perfect for close-up observation. To see a map of typical jellyfish sightings, check ourjellyfish types guide for New York.
Are sea nettles dangerous in New York waters?+
Sea nettles deliver a painful sting, but they're not life-threatening. They're common in the Hudson River estuary and the eastern bays of Long Island from July through September. The sting feels like a sharp burn and leaves a red welt. I've been tagged by one while wading at West Meadow Beach – it's unpleasant, but a vinegar rinse calms it down. If you're swimming, look for their transparent bell with reddish tentacles. Nettle numbers peak in late August. See ourstate animal guidefor the next step.
What other less common jellyfish might you see?+
Occasionally you'll spot the comb jelly (a ctenophore, not a true jellyfish) or the Portuguese man o' war (a siphonophore) if currents bring them up from the south. I saw a man o' war washed up at Rockaway Beach after a storm in 2022 – it's rare, but memorable. Also keep an eye out for the harmless blue button jellyfish (*Porpita porpita*) in the summer. For a full list, see ourNew York jellyfish identification page.
What gear helps you identify jellyfish on the go?+
Once you've started spotting jellies, a quick reference can help. I keep a **Jellyfish Species Chart T-Shirt** handy – it's printed with the main types and their features, so I can ID them right on the beach. ### Jellyfish Species Chart T-Shirt This lightweight tee shows clear illustrations of lion's mane, moon jelly, sea nettle, and more. It's great for learning and teaching others.Check Price and Availability ### Jellyfish Men's T-Shirt A classic tee featuring a stylized jellyfish design. It's comfortable for a day of beachcombing and a conversation starter.Check Price and Availability ### 5Aup Scientifically Accurate Coral Reef Mug This 11oz mug shows accurate reef life including jellyfish. Perfect for your morning coffee while planning your next spotting trip.Check Price and Availability For more wildlife-themed gear, browse ourwildlife tote bags.
Do you get jellyfish in Lake Ontario?+
Yes, freshwater jellyfish (*Craspedacusta sowerbii*) have been reported in Lake Erie and Lake Ontario, but they're rare and tiny (about the size of a penny). They appear in warm, still water in late summer. Don't expect to see them on a typical beach day – they're more common in inland ponds. For New York marine jellyfish, stick to the coast.
What should you do if you get stung by a jellyfish in New York?+
For common stings from moon jellies or sea nettles, rinse with vinegar to neutralize the stingers. Do not use fresh water, which can trigger more nematocysts. Remove any tentacles with a gloved hand or tweezers. If pain persists or you have an allergic reaction, seek medical help. Always check local beach advisories – some beaches post flags when jellyfish are abundant. See ourtour planning ideasfor the next step.
Keep exploring
More places to see jellyfish
More wildlife in New York