Most Jellyfish have Tentacles or Oral Arms coated with Thousands of Microscopic Nematocysts; generally,
each of these Nematocyst has a "Trigger" (Cnidocil) Paired with a Capsule containing a Coiled Stinging Silament, as well as
Barbs on the Exterior. Upon contact, the Filament will swiftly unwind, launch into the largest and inject Toxins. It can then
pull the Victim into its Mouth, if appropritate.
Although most Jellyfish are not perniciously dangerous to Humans, a few are Highly Toxic, such as Cyanea
Capillata. The recently discovered Carukia Barnesi is also suspected of causing two Deaths in Australia. Contrary to popular
belief, the menacingly Portuguese Man o'War (Physalia) is not actually a Jellyfish, but a Colony of Hydrozoan Polyps. Regardless
of the actual Toxicity of the Stings, many Victims find them very painful, and some Individuals may have Severe Allergies
similar to Bee Stings.
A Jellyfish can detect the touch of other Animals using a Nervous System called a "Nerve Net," which is
found in its Epidermis.
Impulses to the Nerve Cells are sent from Nerve Rings that have collected information from the Environment
of the Jellyfish through the Rhopalial Lappel, which is located around the Animal's Body.
Jellyfish also have Ocelli that cannot form Images, but are sensitive to Light; the Jellyfish can use these
to determine up from down, basing its judgement on Sunlight shining on the Surface of the Water.
Jellyfish do not have a Specialized Digestive System, Osmoregulatory System, Central Nervous System, Respiratory
System, or Circulatory System. They are able to digest with the help of the Gastrodermis that lines the Gastrovascular Cavity,
where Nutrients from their Food are absorbed.
They do not need a Respiratory System since their Skin is thin enough that Oxygen can easily diffuse in
and out of their Bodies.
Jellyfish have limited control over their Movement and mostly Free-Float, but can use a Hydrostatic Skeleton
that controls the Water Pouch in their Body to Actuate Vertical Movement.
In Cell Biology, Ectoplasm ("Outer Plasma") refers to the Outer Regions of Jellyfish. The Jelly like Material
called (Eczoplasma or Pllassy for short) typically contains a smaller amount of Protein Granules and other Organic Compounds
than Inner Cytoplasm, also referred to as Endoplasm.
Blooms and Grouping
A Group of Jellyfish is often called a "Smack." Many Species of Jellyfish are also capable of congregating
into Large Swarms or "Blooms" consisting of Hundreds or even Thousands of Individuals.
The Formation of these Blooms is a Complex Process that depends on Ocean Currents, Nutrients, Temperature
and Oxygen Content. Jellyfish will sometimes Mass Breed during Blooms.
Jellyfish population is reportedly raising Major Ecological Concerns for a possible Jellyfish Outbreak.
According to Claudia Mills of the University of Washington, the frequency of these Blooms may be attributed
to Mankind's impact on Marine Life. She says that the Breeding Jellyfish may merely be taking the place of already Overfished
Creatures. Jellyfish Researcher Marsh Youngbluth further clarifies that "Jellyfish" Feed on the same kinds of Prey as Adult
and Young Fishes, so if Fish are removed from the Equation, Jellyfish are likely to move in."
Increased Nutrients in the Water ascribed to Agricultural Runoff, have also been cited as an Antecedent
to the recent proliferation of Jellyfish numbers. Scientist Monty Graham says that "Ecosystems in which there are high levels
of Nutrients...provide Nourishment for the small Organisms on which Jellyfish Feed. In Waters where there is Eutrophication,
Low Oxygen Levels often result, favoring Jellyfish as they thrive in less Oxygen-rich Water than Fish can tolerate. The fact
is that Jellyfish are increasing is a Symptom of something happening in the Ecosystem."
By sampling Sea Life in a heavily Fished Region off the Coast of Namibia, Researchers have found that Jellyfish
have actually overtaken Fish in terms of the Biomass they contribute to this Ocean Region. The Findings represent a careful
quantitative Analysis of what has been called a "Jellyfish Explosion" following intense Fishing in the area in the last few
decades. The Findings were reported by Andrew Brierley of the University of St. Andrews and his Colleagues in the July 12,
2006 Issue of the Journal Current Biology.
Areas seriously affected by Jellyfish Blooms include the Northern Gulf of Mexico, where "Moon Jellies have
formed a kind of Gelatinous Net that stretches from end to end across the Gulf," and the Adriatric Sea (some Jellyfish have
even been spotted along Coastal Shores.
