Jellyfish are among the most dangerous creatures in the ocean. They sting humans, fish, turtles, birds and even sharks. In fact, some species can kill people within minutes. And while we don’t know exactly how many jellyfish there are in Florida waters, we do know it’s enough to make us want to avoid swimming near them.
Moon Jellyfish in Florida
Moon Jellyfish are found in Florida waters, they live near coral reefs and other marine life. They are also known as moon jellies because they look like a jellyfish, but are actually sea creatures. What makes them unique is their ability to change color.
The moon jellyfish has two types of cells. One type changes from light blue to dark blue when exposed to sunlight. This allows the creature to camouflage itself against its surroundings.
The jellyfish feeds mainly on phytoplankton, although it sometimes consumes larger animals like copepods and bivalves. Jellyfish usually feed during daylight hours; however, some species are known to feed at night and during periods of low light intensity. Some species have been observed to migrate upriver when food supplies become scarce.
Moon jellyfish are generally harmless to humans, although occasionally they sting when handled. However, there have been reports of people being stung while swimming in the ocean and even while walking near the water’s edge. In addition, there have been reports that children might be stung accidentally while playing in the sand during beach trips.
This creature have long tentacles that contain tiny stinging cells called nematocysts. These nematocysts are used to capture prey such as small fish, shrimp, and planktonic crustaceans. When touched, the tentacle contracts slightly, causing the nematocysts to discharge. If contact is maintained, the nematocysts release toxins that paralyze the prey.
Moon jellyfish typically grow up to 40 cm (16 inches) in diameter. Their bell is usually pale yellow or cream colored, but sometimes it appears greenish. Some individuals may be entirely transparent. The body is oval shaped and flattened like a pancake. The mouth is located near the center of the underside of the bell. The tentacles emerge from the sides of the bell and extend outwards. Each tentacle contains nematocysts that can fire when triggered.
Moon jellyfish live in shallow coastal waters where they feed on plankton. During periods of low tide, moon jellyfish congregate in large numbers around reefs and rocky shores. Although they prefer cooler temperatures, they can tolerate warmer water.
Moon jellyfish reproduce sexually. Females release eggs and sperm into the water column. The eggs hatch into free-swimming larvae called planula larvae. Planulae develop over several days and eventually settle onto the bottom. After settling, the planulae metamorphose into polyps. Polyps form buds, which become reproductive structures known as gonophores.
Moon jellyfish do not swim well; they simply float along with the current.
Moon jellyfish, Aurelia aurita, are preyed upon by many different species of fish, birds, mammals and invertebrates. A few of these include the following:
• Manta ray (Mobula birostris)
• Sea turtles (Caretta caretta, Dermochelys coriaria)
• Seabirds (e.g., gulls, terns, albatrosses)
• Sharks (e.g., bonnethead shark, nursehound shark, tiger shark)
• Fish (e.g., Pacific cod, Atlantic halibut, European hake)
• Amphipods (e.g., moon jelly amphipod, moon jelly shrimp)
Moon Jellyfish in Florida to Human
They’re harmless to humans unless touched or ingested. But because they can cause irritation, even a minor sting can lead to rashes. And while they don’t pose a threat to human health, they do clog up equipment used to clean the water. We have an article about The Dangerous Florida Jellyfish.
If you find yourself swimming through the waters off Florida, look out for moon jellyfish. They have tentacles longer than your arm, but luckily, they only sting when touched.
Have you ever seen moon jellyfish in Florida? Share your experience below!
Thanks for reading!