Having no bones, brain, or heart, the jellyfish are the most unusual marine creatures you can come across. Although their lack of bones makes it difficult to trace their fossil, some scientists are convinced that these creatures have been around for over 700 million years, making them three times older than the dinosaurs. Although we call them fish, these creatures aren’t truly fish but gelatinous zooplanktons.
There are more than 10,000 recognized species of jellyfish in the world, out of which these eight jellyfish can be found in Florida:
- Moon Jellyfish
- Cannonball Jellyfish
- Blue Button Jellyfish
- Mushroom Cap Jellyfish
- Altantic Sea Nettle Jellyfish
- By-the-wind Sailor Jellyfish
- Portuguese Man o’ War Jellyfish
- Mauve Stinger Jellyfish
In this article, we will learn about these eight species: what do they look like, where are they found, how long do they live, what do they eat. Moreover, we will also read fascinating facts about some of them.
- Moon Jellyfish (Aurelia aurita)
- Cannonball Jellyfish (Stomolophus meleagris)
- Blue Button Jellyfish (Porpita porpita)
- Mushroom Cap Jellyfish (Rhopilema verrilli)
- Atlantic Sea Nettle Jellyfish (Chrysaora quinquecirrha)
- By-the-wind Sailor Jellyfish (Velella velella)
- Portuguese Man o’ War (Physalia physalis)
- Mauve Stinger (Pelagia noctiluca)
Moon Jellyfish (Aurelia aurita)
- Genus – Aurelia
- Family – Ulmaridae
- Class – Scyphozoa
- Order – Semaeostomeae
- Lifespan – about 12-18 months
- Diameter – 25-40 centimeters (10-16 inches)
- Population – abundant
The Moon Jellyfish is a species of scyphozoan jellyfish that is also known by the names of “Moon Jelly”, “Common Jellyfish”, and “Saucer Jelly”.
Appearance: Moon Jellyfish has an entirely translucent body, which means that you can see their insides clearly from a fair distance. On the fringe of its bulbous, bell-shaped body, short tentacles are attached. Each of these tentacles is lined with stinging cells (nematocysts). They also possess four oral-arms, all of which are longer than the tentacles.
The best way to differentiate this jellyfish from the other scyphozoan jellyfish is by looking at their gonads; it has four horseshoe-shaped gonads at the center of its bell.
Habitat and range: You can find the Moon Jellyfish worldwide in the tropical as well as subtropical oceans. In North America and Europe, it is commonly found along the coast of the Atlantic.
Diet: Organisms like mollusks, protozoan, rotifer, young polychaetes, the larvae of the tunicates, and eggs of diatoms and other fish make up the primary diet of the Moon Jellyfish. However, it is only when it can’t find these organisms that it feeds on the zooplankton, like ctenophores and hydromedusae.
It uses its tentacles to catch and bring food to its gastrovascular cavity, where the digestive enzymes act upon it to break it down.
Does the Moon Jellyfish sting humans? Yes, the Moon Jellyfish can sting. However, since the venom from their sting is too mild to do any real damage, they are considered harmless.
Fun fact: In China, the Moon Jellyfish are consumed as food.
Cannonball Jellyfish (Stomolophus meleagris)
Genus – Stomolophus
Family – Stomolophidae
Class – Scyphozoa
Order – Rhizostomeae
Lifespan – about 3-6 months
Diameter – 25 centimeters (10 inches)
Population – decreasing in some parts of the world
Also referred to as the “Cabbagehead Jellyfish”, the Cannonball Jellyfish is a jellyfish species that belongs to the genus of true jellyfish (Stomolophus). Both their names are descriptive of the shape of their bell.
Appearance: Cannonball Jellyfish has a robust, medium-sized body, with its bell-shaped, somewhat like a dome. It has a milk-colored body with a pigmented coloration near the rim of the bell. In the Atlantic, the pigment is usually brown, while in the Pacific, it is often blue. Just underneath the bell, you can find a cluster of oral arms extending around the mouth cavity. These arms come in handy while catching food.
Habitat and range: Cannonball Jellyfish is found abundantly on the southeast coast of the United States both in summer and fall. In the Pacific Ocean, its range extends from the South China Sea to the Sea of Japan and from California to Ecuador. In the mid-west Atlantic Ocean, you can find it between New England and Brazil. Warm, semi-tropical saltwater is most ideal for their growth.
Diet: Cannonball Jellyfish mainly feeds on zooplankton, all forms of the red drum larvae, larvae of snails, and mollusks. It has a peculiar feeding method, wherein it sucks the water along with the food when its bell contracts.
Does the Cannonball Jellyfish sting humans? Yes, it can. Its sting causes a minor irritation to your skin or eyes. However, when the Cannonball Jellyfish is disturbed, it releases a toxic mucus. It is this toxin that you should be worried about since it can cause cardiac problems in humans. Animals are equally vulnerable to this toxin.
Fun Fact: Unlike other jellyfish that are dependent on the waves or the wind for movement, the oral arms of the Cannonball Jellyfish help it to swim.
Blue Button Jellyfish (Porpita porpita)
- Genus – Porpita
- Family – Porpitidae
- Class – Hydrozoa
- Order – Anthoathecata
- Lifespan – unknown
- Diameter – 3 centimeters (1.81 inches)
Also referred to as the “Blue Jelly”, the Blue Button Jellyfish is a hydroid that derives its name from its button-like structure. Although it is popularly known as jellyfish, it doesn’t belong to the true jellyfish family.
Appearance: Blue Button is a small marine organism, consisting of only two significant body parts. The first is the float: a flat, circular disc-like structure colored in golden brown. Attached to the float is the hydroid colony, which is similar to the tentacles of the jellyfish. Each strand of the colony is further branched out into several branchlets. The color of the hydroid colony ranges from blue to turquoise. The mouth of the Blue Button is located beneath its float and is used both for food intake and the discharge of the waste.
Habitat and range: The Blue Button inhabits the tropical and subtropical waters of the Indian, Pacific, and Atlantic Oceans. Moreover, it is also found in the western parts of the Arabian Sea and the Mediterranean Sea.
Diet: The primary diet of the Blue Button consists of either smaller crustaceans or the larvae of all crustaceans. Being a drifter on the ocean surface, it has to compete with the other Pleustons for hunting prey.
Does the Blue Button Jellyfish sting humans? The Blue Button does not have a powerful sting and causes only a mild irritation in humans. However, recently, several cases of dermatitis have been recorded by their contact.
Fun fact: The Blue Button Jellyfish is hermaphrodite, consisting of both the male and female sexual organs so that it can reproduce on its own.
Check out our list of 311 Blue Fish Names
Mushroom Cap Jellyfish (Rhopilema verrilli)
- Genus – Rhopilema
- Family – Rhizostomatidae
- Class – Scyphozoa
- Order – Rhizostomeae
- Lifespan – unknown
- Diameter – 35-50 centimeters (13.77-19.68 inches)
Also referred to as “Sea Mushroom Jellyfish”, the Mushroom Cap Jellyfish is a jellyfish species that has been named after the mushroom-like shape of its medusae.
Appearance: The Mushroom Cap Jellyfish has a medium-sized bell that is shaped like a mushroom. The bell is translucent and has a gelatinous texture, colored in pale brown, pink, yellow, green, or blue. You can also find light brown pigmentation on its margins occasionally.
Unlike the other jellyfish species, the Mushroom Cap Jellyfish has no tentacles. However, it possesses eight oral arms with finger-like appendages branching out of them. It has nematocyst warts underneath its bell, used to immobilize its prey.
Habitat and range: The Mushroom Cap Jellyfish is found in abundance along the coast of the Gulf of Mexico, New England, and North Carolina. However, during the winter, you can also find it in the Chesapeake Bay.
Diet: The Mushroom Cap Jellyfish feeds on the tiny parts of plankton it can find floating around.
Does the Mushroom Cap Jellyfish sting humans? No, the Mushroom Cap Jellyfish cannot sting humans, since its stinging cells are located within its bell.
Atlantic Sea Nettle Jellyfish (Chrysaora quinquecirrha)
Lifespan: about 1 year
Diameter: about 40 centimeters (16 inches)
Population: steadily increasing; especially near areas of human settlements
Also known as the “East Coast Sea Nettle” or “US Atlantic Sea Nettle”, The Atlantic Sea Nettle is a sea nettle species found on the Atlantic coast of the United States.
Appearance: The Atlantic Sea Nettle is closely related to the Pacific Sea Nettles; only the latter is smaller in size than the latter and has more color variations. It has a radically symmetrical, semi-transparent body with the mouth cavity located outside the bell. The mouth is surrounded by tentacles on all sides that are responsible for catching food. On its bell, you can find small, white dots and dark brown stripes, scattered more densely near the rim.
Habitat and range: As you can gather by their name, the Atlantic Sea Nettle is found only on the Atlantic coast of the US. If you spot their look-alikes in other parts of the world, they are probably other members of the Sea Nettle family.
Diet: The Atlantic Sea Nettle first immobilizes its prey by stinging them with its tentacles. Once they are immobilized, the tentacles carry them to the gastrovascular cavity, where the digestion takes place. It primarily feeds on ctenophores, zooplanktons, crustaceans, and other jellies. In the scarcity of these organisms, it can also eat worms, minnows, mosquito larvae, and anchovy eggs.
Does the Atlantic Sea Nettle Jellyfish sting humans? Yes, it can sting. The sting can have a severe effect on smaller organisms, such as their prey. However, it can’t cause any significant damage to humans unless they have a fatal allergic reaction.
Fun fact: All the Sea Nettles, including the Atlantic Sea Nettles, lack respiratory as well as excretory organs.
By-the-wind Sailor Jellyfish (Velella velella)
Diameter: 10 centimeters (3.93 inches)
Among all the jellyfish species you can find in Florida, the By-the-wind Sailor is the most unusual. It is a hydrozoan species that floats on the surface of the sea. It has several other names, such as “Sea Raft”, “Purple Sail”, “Little Sail”, etc. Some people also simply call them by their generic name “Velella”.
Appearance: The body of the By-the-wind Sailor consists of a small, oval disc that ranges from blue to purple in color. This disc is known as a float. A thin, semi-circular fin-like structure is attached diagonally to the float, known as the sail. The sail is essential to its movement, for it catches the direction of the wind in order to move with the ocean current. At the bottom of the float, tiny tentacles are attached that hangs down in the water.
Habitat and range: The By-the-wind Sailor is found in the warm, temperate waters throughout the world. Like we mentioned earlier, it doesn’t live inside water so much as it floats on the surface.
Diet: The By-the-wind Sailor catches its prey (generally plankton) using the tentacles attached to the float’s bottom.
Does the By-the-wind Sailor sting humans? Although the tentacles of the By-the-wind Sailor consist of nematocysts, they are mostly used on their prey. On humans, the sting has an insignificant effect.
Fun fact: Because the By-the-wind Sailor floats on the surface of the ocean, it is as prone to sunburn as we are. However, to combat this, it has built-in blue pigments that block the radiation of the sun.
Portuguese Man o’ War (Physalia physalis)
Lifespan: about 1 year
Body length: 9-30 centimeters (3-12 inches) long and 15 centimeters (6 inches) wide
Commonly known as “Bluebottle” and “Floating Terror”, the Portuguese Man o’ War is a hydrozoan that lives on the surface of the ocean and is popular for its deadly sting.
Appearance: Although the Portuguese Man o’ War is popularly believed to be a jellyfish due to its tentacles and pneumatophore, it is not a true jellyfish.
The pneumatophore of the Portuguese Man o’ War is translucent and stays above the water surface. It might appear to be pale blue, purple, or pink. It is filled with gases like carbon monoxide, carbon dioxide, argon, oxygen, and nitrogen. On top of it, a sail-like structure is attached, which helps it to move.
Attached to the gas bladder are three different polyps that perform different functions. The first ones are the gonozooids, which perform the reproductive functions. The second, the gastrozooids, are responsible for their feeding and digestion. The third is the dactylozooids, which are tentacles extending up to 165 feet. These tentacles are either blue or purple in color and consist of nematocysts that paralyze their prey.
Habitat and range: The Portuguese Man o’ War is known to inhabit tropical and subtropical waters, and is found in the Atlantic as well as Indian Oceans.
Diet: The Portuguese Man o’ War feeds on crustaceans, worms, and small fish.
Does the Portuguese Man o’ War sting humans? The sting of the Portuguese Man o’ War can be fatal for humans. Its sting leaves red welts on our skin that can last up to four days. Although its sting is usually painful for the first few hours, in some cases, the venom can even reach our lymph nodes, causing allergic reactions such as a swollen larynx. In extreme conditions, it can even lead to airway blockage and cardiac arrest and potentially kill us.
Fun fact: Although the Portuguese Man o’ War appears like a single organism, it actually has four different organisms, known as “Zooids”, that function together as one. Such organisms are known as “Siphonophores”.
Mauve Stinger (Pelagia noctiluca)
Diameter: 12-15 centimeters (4.72-5.90 inches)
The Mauve Stinger is known by several other names such as “Luminous Jellyfish”, “Purple Jellyfish”, “Purple Stinger”, “Night-light Jellyfish”, and “Purple-striped Jelly”.
Appearance: Mauve Stinger has a fairly small body with varying colors such as pink, yellow, mauve, or light brown. Its gastrovascular cavity has only one opening that is used both for excretion as well as ingestion.
There are four oral arms attached to its bell, having crenulated margins that act as a feeding surface. It also possesses eight tentacles that contain nematocysts, used to immobilize their prey.
Habitat and range: The Mauve Stinger inhabits warm waters and temperate seas. It is commonly found in Atlantic Canada, the North Sea, the Gulf of Mexico, and the Mediterranean.
Diet: Mauve Stinger is an opportunistic feeder and can feed on siphonophorans, plankton crustaceans, larvaceans, arrow worms, fish eggs, and larvae. It is also known to be cannibalistic in some areas.
Does the Mauve Stinger sting humans? The Mauve Stinger contains stinging cells both on its tentacles and inside its bell. Its sting is painful to humans and can cause redness, swelling, and rash that might last for a couple of weeks. In some cases, the symptoms of diarrhea, dizziness, and vomiting are also noticed.
Jellyfish are truly extraordinary creatures, with 98% of their body consisting purely of water. Did you know that some of them even lack respiratory organs? Fascinating, isn’t it? It is no wonder that people are in awe of these creatures, astonished at how they perform even the most basic functions.
Well, you might have learned a lot more about the eight species that can be found in Florida by now. All of them have a distinct appearance, as you must have noticed. Therefore, it is difficult to confuse them with one another.
The next time you come across one, we hope you will be able to recognize it. However, be cautious of their sting and don’t get too close.