Since 1983, biologists with the Texas Parks and Wildlife Department have trawled the Gulf coastline every month, and the same handful of jellyfish keep turning up in the nets. Moon jellies, sea nettles, and cabbageheads make up most of the catch, but swimmers and beachcombers also run into a giant predatory pink jelly and a stinging box jelly with a nickname borrowed from a very different, far more dangerous animal. Knowing the different types of jellyfish in Texas helps beachgoers tell a harmless drifter from one worth avoiding.
Texas’s more than 350 miles of Gulf shoreline create ideal habitat for these gelatinous drifters, with numbers rising and falling by season, salinity, and water temperature. This rundown covers five species native to types of jellyfish found between South Padre Island and Galveston, along with what makes each one worth a second look. For a broader survey of the gelatinous life sharing these same warm currents, see this guide to jellyfish in the Gulf of Mexico.
| Species | Typical Size | Sting Severity | Peak Season |
|---|---|---|---|
| Moon Jelly | Up to 1.5 feet across | Mild | Late spring–midsummer |
| Sea Nettle | Several inches, long trailing tentacles | Painful | Late spring–midsummer |
| Cannonball Jellyfish | Up to 10 inches | Mild | Late summer–fall |
| Pink Meanie | Up to 50 lbs, tentacles to 70 feet | Mild | Late summer–fall |
| Atlantic Sea Wasp | Bell 5–6 inches | Very irritating | August–October |
1. Moon jelly
The moon jelly (Aurelia aurita) is probably the jellyfish most Texas beachgoers picture first, and for good reason. It is one of the most common species of jellyfish in the world, with a translucent, saucer-shaped bell that grows from a few centimeters to about a foot and a half across.
According to Texas Parks and Wildlife field notes, moon jellyfish and sea nettles are most common in bay and Gulf waters from late spring through midsummer, while other local species peak later in the year. Moon jellies share this same window with sea nettles, often drifting in the same current lines along beaches from Galveston to South Padre Island.
Once a moon jelly washes ashore or dies at sea, it rarely goes to waste. More than 1,000 animal species are known to feed on jellyfish carcasses, according to a marine biologist at Texas A&M University at Galveston, and moon jellies drift through the same bay systems that support countless native types of fish in Texas.
Pro Tip: Look for four horseshoe-shaped markings near the center of the bell — these are the moon jelly’s gonads, and they’re the easiest way to identify this species from a distance without touching it.
2. Sea nettle
The sea nettle (Chrysaora quinquecirrha) carries a reputation that fits its name. Its translucent, amber-tinted bell is marked with thin reddish-brown stripes, and unlike the moon jelly, it delivers a sting that beachgoers notice right away.
Despite the discomfort, sea nettles are actually the most abundant true jellyfish along the Texas coast. Trawl surveys run by Texas Parks and Wildlife from 1982 through 2011 found stinging nettles were nearly twice as abundant as cabbageheads and moon jellies combined in coastal waters. That abundance, paired with a sting that lingers, puts the sea nettle near the top of most lists of poisonous animals in Texas that swimmers are warned about each summer.
The sting isn’t considered dangerous to most healthy adults, though it can be painful enough to end a swim early. Stranded sea nettles on dry sand can still sting if handled, since their nematocysts remain active well after the animal has washed ashore.
Important Note: This article is for general educational purposes. Anyone with a severe reaction to a jellyfish sting, or symptoms like difficulty breathing, should seek medical attention rather than relying on home remedies.
3. Cannonball jellyfish
The cannonball jellyfish (Stomolophus meleagris) goes by several nicknames along the coast, including cabbagehead and jellyball, all describing its dome-shaped, tentacle-free bell. Per Texas A&M University at Galveston, this translucent jelly can grow up to 10 inches across and is a regular presence in both bay and Gulf waters.
Despite its sturdy, bell-shaped appearance, the cannonball is one of the gentler jellies on this list. It has no trailing tentacles, though stinging cells inside the bell itself produce a sting generally considered mild compared to the sea nettle’s.
Juvenile pinfish and spider crabs often shelter beneath the cannonball’s bell, gaining protection from predators while they’re still small and vulnerable, a relationship that benefits the young animals without apparently costing the jellyfish anything. It’s one more example of how closely these jellies are tied to the same types of fish that fill Texas bays.
Massive blooms of cannonballs are common in late summer and early fall, when thousands can be seen floating together near the surface. A Harte Research Institute biologist has attributed these blooms to a mix of currents, onshore winds, and cooling water temperatures rather than any single cause.
4. Pink meanie
The pink meanie (Drymonema larsoni) is the giant of this list, with a cotton-candy-pink bell and tentacles that can stretch up to 70 feet, weighing more than 50 pounds in some cases. In the water it looks like a drifting cloud of spun sugar; on the sand, it tends to fade to a drab, hard-to-identify blob within hours.
Scientists only confirmed the pink meanie as a distinct species in 2011, after researchers first noticed large blooms in the northern Gulf of Mexico around 2000. According to the species’ Wikipedia entry, the discovery led researchers to create an entirely new jellyfish family, Drymonematidae — the first new family of true jellyfish described since 1921.
Key Insight: Pink meanies don’t filter plankton like most jellyfish. They actively hunt other jellyfish, wrapping their long tentacles around prey and digesting it with specialized oral arms, with moon jellies as their preferred target.
Harte Research Institute biologist Jace Tunnell has documented pink meanies wrapped around moon jellies in Port Aransas marinas, describing the pairing as a near-guaranteed sighting whenever both species bloom at once, according to Smithsonian Magazine. Without a steady supply of moon jellies to eat, pink meanie populations tend to collapse quickly.
For an animal this size, the sting is surprisingly mild. “The sting is probably a two, for me, out of ten, so not too bad,” Tunnell has said, making the pink meanie far less dangerous than many other venomous animals in Texas despite its intimidating size.
5. Atlantic sea wasp
Despite sharing a nickname with one of the world’s deadliest marine animals, the Atlantic sea wasp found in Texas waters is a different and far less dangerous creature. Locally, “sea wasp” refers to Chiropsalmus quadrumanus, a four-handed box jelly that the Texas Parks and Wildlife database lists among the state’s three native box jellies.
Important Note: The truly dangerous “sea wasp,” Chironex fleckeri, lives in Australian waters and is not found in the Gulf of Mexico. Texas’s sea wasp shares the nickname but not the lethal reputation.
Texas’s sea wasp is a colorless, transparent cubozoan with a bell that typically measures five to six inches across, trailing bundles of seven to nine mauve tentacles from each corner of its body. It has been documented in at least four Texas estuaries, most often within the Galveston Bay system, and shows up seasonally between August and October, delivering what researchers describe as a very irritating sting.
Two other box jellies round out the state’s small cubozoan lineup. Tamoya haplonema has long, milky-yellow tentacles and a sting that’s painful but not lethal, while the mangrove box jelly (Tripedalia cystophora) rarely grows larger than a silver dollar and ranges from greenish-gray to brownish-yellow. Because of its sting, the sea wasp still ranks among the more uncomfortable encounters on any list of dangerous animals in Texas, even without the fearsome reputation of its Australian namesake.
From the harmless drift of the moon jelly to the irritating sting of the Atlantic sea wasp, Texas’s coastal waters host a surprisingly varied cast of gelatinous animals. Most encounters end with nothing worse than an itchy welt, but it pays to look before wading in, especially during peak bloom months in late spring and late summer.
Beachcombers walking the wrack line will often spot gulls, herons, and other Texas water birds picking through stranded jellies for an easy meal, proof that even a dying jellyfish still has a role to play in the coastal food web. For a wider view of what else drifts through these same currents, the guide to jellyfish in the Gulf of Mexico covers species found well beyond Texas’s own shoreline.