They spend this part of their lives as opaque drifting balloons with trailing tentacles. Jellyfish start their lives as larva, tiny cigar shaped creatures that spiral through the water, looking for a rock or something handy to attach itself to. Once firmly in place, the larva metamorphoses into a polyp, rather like a tiny sea anemone.
Colonies of these polyps are created as the polyp clones itself which means a colony can cover an entire boat dock in a matter of days. Some types of polyp form huge shrub-like bushes. When the conditions are right, these polyps bloom in vast numbers and when they bloom, what buds from the polyp are baby jellyfish. When the medusa the immortal jellyfish Turritopsis dohrnii dies, it sinks to the ocean floor and begins to decay.
Amazingly, its cells then reaggregate, not into a new medusa, but into polyps, and from these polyps emerge new jellyfish. The jellyfish has skipped to an earlier life stage to begin again. This was a real mind blower for all of us It can have tentacles that are over 27 meters long - longer than the size of the blue whale which is the biggest mammal in the world!
You might think that a gaggle of geese, a murder of crows, or a clowder of cats sounds interesting, but jellyfish groups have even better names. Toggle navigation Menu. Explore Videos Games. Explore All. More cool posts! Don't wash the area with fresh water -- it could release more venom into your body. Instead, clean it with rubbing alcohol, ammonia, vinegar or urine yes, you read right.
You can also apply meat tenderizer or a mixture of baking soda and water. Any signs of an allergic reaction shortness of breath, hives , wheezing warrant immediate medical attention. Jellyfish have excellent protection against predators: their stinging tentacles are a strong deterrent, and their transparent bodies help them hide. A few animals, such as loggerhead turtles, sunfish and spadefish, eat jellyfish.
Some young fish actually live on or even in jellyfish. They hide out in the tentacles to avoid being eaten by predators until they mature. And some people -- especially in China and Japan -- also eat jellyfish, considering them a delicacy.
Aside from their occasional stings, jellyfish are not generally a nuisance. But in recent years, certain parts of the world -- namely Japan, Australia, and Europe -- have seen a problematic increase in jellyfish populations. Scientists believe the increase in jellyfish numbers may have to do with additional nutrients in the water, climate change or fishing along the coastlines.
Dramatic population increases are called blooms. Some researchers are concerned that the increased numbers of jellyfish could compete for food resources with fish and other marine animals, and eventually bump out native local species.
In large numbers, jellyfish also wreak havoc with local fishing industries by tearing holes in fishing nets and disrupting other fish populations. Jellyfish do best in their natural environment, but many aquariums have jellyfish tanks. People who capture and raise them in captivity must be very careful not to damage their fragile bodies.
It's easier to collect jellyfish in the polyp stage, when they are less vulnerable. Ideally, they should be in a tank free from any sharp corners or obstacles on which they could hurt themselves. In addition, the water needs to have some flow to it because jellyfish primarily move with currents.
This jellyfish looks like a square with its four sides -- hence the name "box. Box jellyfish tend to gravitate toward the mouths of rivers and creeks, and their sting is very painful.
People who have unwittingly been stung can experience intense muscle cramps and difficulty breathing. The name of this type of jellyfish says it all. Deep-sea jellyfish live in very deep waters, as far as 23, feet below the ocean's surface.
They are usually dark-colored -- brown, violet or black. Irukandji are a type of box jellyfish found in Australia. Although they're small about the size of a human thumbnail , their venom is extremely toxic. This type of jellyfish has cnidoblasts on its body as well as its tentacles. The Irukandji's sting is so painful and causes such severe symptoms that scientists have given them a name: Irjukadji syndrome.
Symptoms include high blood pressure, vomiting, headaches, extreme cramping and pain, and a burning sensation. Irukadji syndrome can last up to two weeks, and there's no antidote. Doctors have found that magnesium infusions can bring some relief, but the syndrome can be fatal. This is the type of jellyfish most commonly seen on the shores of North America and Europe. This pink or blue jellyfish usually lives in waters about 20 feet deep.
Its sting is mild, leaving a red, itchy rash. A Portuguese man-o'-war isn't a jellyfish, although it resembles one. They're actually siphonophores -- floating colonies that include four individual animals, each with its own role for example, stinging, feeding, movement and reproduction.
Named for the 18th century ship that it resembles, the Portuguese man-o'-war is a member of the same phylum, Cnidaria , as the jellyfish. Its sting can be very painful and can lead to symptoms such as chills, fever, nausea, vomiting and shock. In some cases, the stings are fatal. Jellyfish are prehistoric creatures that have inhabited oceans around the world for millions of years. Although their gelatinous bodies and graceful movements make them appear to be complex creatures, they are actually quite simple in both form and function.
Jellyfish are planktons that have no bones, brain, or heart. In fact, their bodies are mostly water and have just six major parts. Jellyfish live anywhere from months and range in size from less than an inch to over 7 feet long. Although they are not aggressive creatures by nature, jellyfish are often remembered for their nasty stinging capabilities.
Jellyfish mostly use their tentacles for hunting, but will also sting in self-defense. When jellyfish sting humans, it is always done in self-defense since humans are far too large for any jellyfish to eat. But, aside from the occasional sting, there's no need to fear these water-based creatures from prehistoric times.
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