Top five most dangerous Jellyfish in Florida


Florida is another state in the United States that contains hundreds of miles of beaches. The state is in the shape of a peninsula having water on its three sides while one border is connected with the mainland of the U.S. Florida is famous in the whole world because of its beautiful beaches and marine life. Jellyfish are considered the most striking feature of oceans that enchants the heart of swimmers. Yes, it is also true that some jellyfish are killers and can deliver a painful sting. However, it always seems good to know about this fascinating and attractive beast. 

Top five most dangerous Jellyfish in Florida

Some common jellyfish of Florida are the following;

1. Portuguese Man o War

Portuguese Man o War

The Portuguese man o war is also called the man of war. It is a marine hydrozoan found on Florida beaches. Although the Portuguese man o war is a popular jellyfish on Florida beaches, it is not a real jellyfish. True Jellyfish are single multicellular organisms whereas Portuguese man o wars, like corals, are made up of colonies of specialized individual animals. This species lives on the surface, relying on currents, tides, and wind to capture its inflated sail and carry it to food sources, which is how it frequently ends up on the shore. It traps its food in its tentacles. It feeds on young fish and small fish. Its tentacles, which may range from 10 to 30 meters in length, are armed with venom-filled nematocysts that, if touched by human skin, will administer a terrible sting. Never contact a Portuguese man o war because these nematocysts are active even after the animal is dead. The welts remain for 1 to 2 weeks, and skin rashes can appear 1 to 4 weeks after the sting. Their stings can cause a red line with small white sores. In serious cases, blisters and welts which appear as a string of beads may appear. Its stings are not different than other jellyfish stings. Their stings and bits of a tentacle can be removed by vinegar.

2. By the wind sailor

By the wind sailor

Velella is a single genus hydrozoan belonging to the Poritidae family. Velella, a worldwide free-floating hydrozoan that dwells on the open ocean’s surface, is its sole known species. Sea raft, by the wind sailor, purple sail, small sail, or simply Velella are some of its common names. The by-the-wind sailor is another type of jellyfish which is found on Florida beaches. This is also not a real jellyfish. It is just like the Portuguese man o war, a colonial species. It works just like Portuguese man o war. It uses tides, currents, and wind to traverse the open sea, with tentacles trailing below to ensnare and envenomate prey. The toxins which are present in its nematocysts are not toxic to humans but they can cause irritation and itching of the skin and eyes if these are contacted with the venom. Marine slugs, various mollusks, and snails are their major predators. It reproduces by budding off portions of the colony asexually. The bits that bud off are known as medusa and are fashioned like small bells. Both male and female components are present. 

3. Lion’s Mane

Lion’s Mane

Cyanea capillata is the scientific name for the lion’s mane jellyfish. It may be the world’s largest jellyfish, so it is known as the giant jellyfish. It is also known as arctic red jellyfish or hair jelly. Its lifespan is 12 months. It features a bell that is more than two meters across, which is the main component of its body. It feeds on tiny crustaceans, small fishes, fish larvae and eggs, copepods, and other jellies, especially moon jellies. It can only be found in the northern waters, such as the Atlantic, Pacific, and Arctic oceans. It can live in cool water. Throughout their adult lives, they like to float near the surface in open water, yet they end up spending their days in shallow bays. They rarely travel deeper than 66 feet. Its stings are painful but are rarely fatal. If someone gets stung by it, he should move away from the water and should observe the area of the sting. If some tentacles are present on the skin, do not touch them with your hands. These remnants can be removed by using tweezers.

4. Nomura’s Jellyfish

Nomura’s Jellyfish

The world’s largest jellyfish, Nomura’s jellyfish, is another contender, with some individuals becoming slightly larger than a lion’s mane, their bell can reach a diameter of 6.5 feet. They are capable of weighing 450 pounds. It feeds on small plankton, using its many microscopic mouths to gain this size. They are also becoming increasingly common, to the point that they are causing problems for Japanese fishermen. Global warming may be contributing to their growing numbers. Every year, hundreds of thousands of people are stung by this massive species. Its poison produces redness, swelling, and excruciating agony, as well as shock and death in the most severe cases. Its venom is made up of a variety of chemicals. Many of these chemicals are similar to poison present in other organisms like bees, snakes, spiders, and bacteria. Its venom is very fatal to humans. The gigantic jellyfish has a lethal sting so it is one of the most dangerous organisms in ocean waters that swimmers can come across on a beach vacation. If toxins present in its sting can be determined then drugs can be made to cure its stings and deaths can be reduced. 

5. Comb Jellies

Comb Jellies

Comb jellies live in seawater throughout the world. These jellies belong to the phylum of marine invertebrates. Their scientific name is Ctenophora. They have groups of cilia, they use for swimming, and they are the largest animals to swim with the help of cilia. Comb jellies can eat anything because they are carnivorous. Mostly they feed on small organisms that drift along in the water, but larger species can eat fish, crustaceans, and even other comb jellies and jellyfish. Ctenophores, often known as comb jellies, are pelagic marine carnivores that are transparent and delicate. They feature three layers, biradial symmetry, and an oral-aboral axis of symmetry. There are two cell layers and a thick cellular mesoglea. When water temperatures warm to 66-73 degrees then breeding occurs. This water temperature mostly warms to this degree at night. Both male and female reproductive organs are present in comb jellies and they can fertilize themselves. Each comb jelly discharges about eight thousand eggs per spawn. They can regenerate both their body parts and brains. These jellies do not sting but their tentacles have adhesive cells that discharge mucus-like materials to hold prey. These cells are called colloblasts. They are not dangerous to humans, but they wreak havoc on the environment. The reason is that they have no predators.   


Jellyfish are found on all coastlines of Florida. Some are dangerous and cause serious complications but many are harmless and maintain the delicate balance of aquatic life. So if you encounter any deadly jellyfish then there is no need to worry. In most cases, pain relieves on its own after some time. But some conservative such as washing the site of the sting, use of analgesics, and any sea-safe lotion can be helpful.