Jellyfish

and Jelly-like Organism

There’s something glimmering on the beach, but what could it be?

Jellyfish are frequently spotted washed up on the shore and capture many beachgoers’ interest. Many of these marine invertebrates possess distinct characteristics, such as a dome-shaped bell and tentacles that provide a stinging attack to hunt prey or provide defense. Jellyfish play a critical role in the food web, serving as food for birds and turtles. The most common jellies around Fort Matanzas are the Moon jelly, Cannonball jelly, and the Portuguese Man-o-War which is technically not a jellyfish but a siphonophore.

 

C. Leverett

The Moon jelly (Aurelia aurita) measures approximately 12 inches (30 cm) across its saucer shaped bell that is mostly clear, with its four lobe-shaped gonads visible. Females’ gonads are yellow while males’ are violet-pink. Moon jellies move around mostly by relying on the ocean current although, when needed, they will contract and pulse their bell for limited movement. Moon jellyfish will use their four short tentacles to feed upon plankton, mollusks, and crustaceans. Their stings are relatively harmless, yet they may cause skin irritations if touched.

 

The Portuguese Man-of-War (Physalia physalis) is not a jelly but a hydralike animal that is part of group of organisms called siphonophores. Siphonophores are unique as they are comprised of many genetically identical zooids, organisms that function together to survive. In this case, one zooid controls reproduction, another controls the hunting, one controls the digestion, and one functions as the gas-filled float. The Portuguese Man-of-War can be recognized by its violet-blue balloon-like float that rests on the surface of the water along with its stinging tentacles that hang an average of 30 feet long below the water’s surface and can even reach up to lengths of 100 feet. Its tentacles are used to capture small fish and can deliver painful stings, so be alert if you see them washed ashore.

 

The Cannonball jellyfish (Stromolophus meleagris) has a firm, rounded bell that displays brown along its margin. It measures up to 8 inches (20 cm) and has no marginal tentacles. While it can still sting from its short oral arms, which are mostly used to eat plankton, it has little to no venom that will only cause a tingle if touched. Both the Moon jelly and the Cannonball jellyfish are found in open ocean waters, and both are most abundant during the summer season.

 

In case of a Jellyfish Sting

If you get stung by a jellyfish, here are some remedies to ease the pain or reaction:

· Remove excess tentacles with a credit card or tweezers

· Rinse with sea water

· Apply vinegar, rubbing alcohol or baking soda to help neutralize the sting

· Seek medical assistance in case of an allergic reaction