Jellyfishes are members of the subphylum Mesusozoa. They are marine animals with bells shaped like umbrellas and trailing tentacles.
There are not many animals that have a life cycle as complicated as the Jellyfish. But as complex as their life cycle is, they have continued and existed for millions of years. They are reproducing, living in groups, and preserving their lives.
So, let’s answer some pertinent questions about this creature.
What is a group of Jellyfish called?
A group of Jellyfish is called a smack. Bloom is also another term for describing a group of Jellyfish.
Bloom is mainly for large amounts of Jellyfish gathered in a small space.
This post contains interesting information about the jellyfish. Are you interested in knowing more about this amazing creature? Keep reading!
The Anatomy Of A Jellyfish
The external structure varies from one Jellyfish to another, but their internal makeup is all the same.
An adult Jellyfish body consists of a bell-shaped hood enclosing its internal structure from which the tentacles appear suspended.
They have a particular kind of cell that covers each tentacle. It is called the ‘cnidocytes.’ These cells are harmful to other animals.
The ‘Rhizostomeae,’ order in the jellyfish class, doesn’t have tentacles and structures at the bell edges but possesses eight highly branched oral arms.
Generally, Jellyfish do not have brains or sense organs. They, therefore, perceive stimuli such as odor, danger, and light quickly through the nervous system and a small sensory structure.
They feed on little fishes or zooplankton, caught within their tentacles. They swim very slowly, but they are passive drifters, possessing an excellent way of forcing their prey into their tentacles by rhythmically opening and closing their bell-like bodies.
In addition, the majority of the Jellyfish are dangerous to humans, and some are highly toxic. An example is the Deep Spider fish, also known as Lion’s mane Jellyfish
The Physalia is not a Jellyfish but a colony of hydrozoans. These organisms are related to the Jellyfish, but they belong to the Phylum ‘cnidaria’.
The Life Cycle Of A Jellyfish
The Jellyfish have two critical phases they undergo depending on the condition of their environment.
When they are attached to a coastal reef, it is a phase called the ‘polyp.’ In this phase, they reproduce asexually by budding. When the Jellyfish are around or among the plankton, a stage called ‘Medusa’ is what they undergo.
This phase (Medusa) is known to be a sexual reproductive stage of the Jellyfish whereby their eggs get fertilized, and they develop into free-swimming ‘planula larvae.’
The larvae float about the water’s surface for a particular interval; then, they go to settle beneath the sea and stick to one end. There they began to develop into Polyps, feeding and growing.
Most of the polyps begin to form buds and cut off tiny Jellyfish called ‘Ephyra larva.’ They are primarily Immature. After these processes, they develop into adult jellyfish.
How Does The Jellyfish Move
Jellyfish are the most efficient swimmers of any animal. Their bell-shaped bodies expand and contract as they move through the water. In similar studies, Jellyfish had a 48 percent lower cost of transport than other animals.
The mechanism, known as passive energy recapture, is only effective in tiny Jellyfish moving at slow speeds.
How And What Do They Eat?
Jellyfish are parasitic cnidarians that feed on fish eggs, crustaceans, larvae, small fish, and planktonic organisms and voiding undigested waste through their mouths. They hunt passively by sinking through the water or using their tentacles as drift lines.
Some species are omnivorous, consuming both microplankton and phytoplankton. The upside-down Jellyfish (Cassiopea andromeda) hunts small animals to supplement its diet. This feeding process gets accomplished by releasing tiny balls of living cells made up of mesoglea.
Where Do Jellyfish Live?
A jellyfish that lives in freshwater is known as a freshwater jellyfish. The hydrozoan jellyfish Craspedacusta sowerbii is the most well-known freshwater Jellyfish.
The upside-down Jellyfish of the genus Cassiopeia typically live on the bottom of shallow lagoons. They pulsate gently with their umbrella top facing down to stay buoyant. The species then attach themselves to seaweed, rocky or other material on the seafloor.
Jellyfish in Roscoe Bay ride the current at ebb tide until they reach a gravel bar, then descend below the wind. They remain in calm waters until the tide rises and sweeps them back into the bay. Some species actively avoid freshwater from snowmelt in the mountains.
Do Humans Eat Jellyfish?
Jellyfish is a meal in some parts of Asia, primarily in Southeast Asia. Twelve species of scyphozoan jellyfish from the Rhizostomeae order get harvested for food.
These countries, China, Japan, Korea, and the United States, are all home to Jellyfish.
You can prepare Jellyfish in a variety of ways. Traditional methods include the removal of the mucous membranes, gonads, and oral arms.
Jellyfish prepared in this manner retain 7–10% of their original weight. Freshly processed Jellyfish is white, creamy, and eventually turns yellow or brown.
Processed Jellyfish are often served cooked or raw in China and Japan. They do the dish with a dressing of oil, soy sauce, vinegar, and sugar. In Japan, cured Jellyfish get rinsed, cut into strips, and served as an appetizer.
Is A Jellyfish Venomous?
Nematocysts, a type of specialized stinging cell, are used by Jellyfish. When a jellyfish tentacle comes in direct contact with the skin, millions of nematocysts pierce the skin and inject venom. The poison of a few species only harms humans.
Jellyfish stings can cause mild discomfort up to extreme pain and death. Jellyfish kill 20 to 40 people in the Philippines alone each year. The Spanish Red Cross treated 19,000 stinging swimmers along the Costa Brava in 2006.
Vinegar may help with box jellyfish stings, but it will not help Portuguese men of war stings. The most effective way to relieve pain from a Physalia sting may be to immerse it in hot water. Rubbing wounds with alcohol, ammonia, freshwater, or urine is not advisable.
Interesting Facts About Jellyfish
They existed millions of years before dinosaurs did:
Because jellyfish lack bones, fossils are scarce. Despite this, scientists have evidence that these creatures have been in existence for 500 million years.
The jellyfish presence in the oceans is likely to date back to 700 million years ago. That is approximately three times the age of the first dinosaurs.
Some species have eyes:
Some jellyfish can see despite their simple body design.
Surprisingly, the workings of their vision may be complex. The box jellyfish, for example, has twenty-four eyes, and two of its eyes can see in color. It’s also thought that this animal’s complex array of visual sensors makes it one of the few creatures on the planet with a full 360-degree view of its surroundings.
Their food comes out through the same hole it goes in:
Yes! They don’t have a different spot for each of these activities. Food goes in through one hole, and when it is time to pass waste, it goes out from the same hole.
They are one of the deadliest creatures on earth:
All Jellyfish have stinging structures called nematocysts, but the strength of their stings varies greatly depending on the species.
The box jellyfish is the most venomous in the world, capable of killing an adult human with a single sting in just a few minutes. Each box jellyfish is said to contain enough venom to kill more than 60 people.
Their stings are excruciatingly painful to worsen the situation — the pain is more lethal than the venom.
They come in different sizes:
Some jellyfish are so tiny that they are practically invisible as they float in the ocean currents. The smallest are those belonging to the genera Eleutheria and frequently those belonging to Staurocladia.
The world’s most giant Jellyfish, on the other hand, are actual monsters. Cyanea capillata, the lion’s mane jellyfish, is most likely the world’s longest, with tentacles that can reach 37 meters.
However, Nomura’s Jellyfish (titanic), which can make a human diver look like a dwarf, is possibly the world’s most giant Jellyfish by weight and diameter. These animals have a diameter (bell) of about 2 meters and weigh up to 200kg.
They are 98% water:
Jellyfish appear to blend in with their surroundings, gently undulating with the ocean currents, and for a good reason: their bodies are made up of up to 98 percent water. When they wash ashore, their bodies evaporate into the air, and they vanish in a matter of hours.
They have a rudimentary nervous system, a loose network of nerves in the epidermis referred to as a “nerve net,” but no brain. They also lack a heart; their gelatinous bodies are so thin that they can take on oxygen through diffusion.
A group of Jellyfish is a smack or a bloom depending on their numbers in a particular environment. These marine creatures consist primarily of water, and they don’t have a heart or a brain, but have survived millions of years on earth.
So, you now understand the name given to Jellyfish in group, including other crucial information about the creature. The next time you see one or when you’re asked questions about Jellyfish, you won’t shy away.