We all are fond of holidays at sea and can not resist swimming. However, sometimes it can be dangerous enough in order to fall out of love with such events. One of such situation is a meeting a jellyfish that is always hunting to consume something. Thus, we will check when is National Jellyfish Day in 2017 and what does it mean.
Annually, on the 3rd of November, this day is organized and is held to emphasize the role of these amazing animals and also to remember its danger to human life. Many theories about their origin exist but we will find out the most popular.
Zoologists, referring to jellyfish, usually mean all the mobile forms of coelenterate stalking animals (a group of multicellular invertebrates of the animal world) that catch and kill their victims with the help of tentacles.
These amazing animals live only in salty water, and therefore they can be found in all oceans and seas of our planet (except for internal ones), sometimes in enclosed lagoons or lakes with salt water on coral islands. Among the representatives of this class, there are both heat-loving animals and preferring cold waters, species that live only near the surface of the water and such that live only on the ocean floor.
Jellyfish are single animals since they do not communicate with each other, even if the currents knock them together, thus forming a colony.
They received their modern name in the middle of the XVIII century, by a virtue of Carl Linnaeus, who helped us to know what Jellyfish Day in 2017 will be. Moreover, he hinted at the mythical head of the Medusa of the Gorgon, a resemblance to which was noticed by these representatives of the animal world. This name is not without reason because these animals are similar to it.
This amazing animal consists of 98% water and therefore has a transparent body with a slight shade, which in appearance resembles a jelly-like bell, umbrella or disk, moving by shrinking the muscles of the bell wall.
There are tentacles along the edges of the body, the shape of which directly depends on the species to which it belongs: in some, they are short and dense, others have long and thin ones. Their number can range from four to several hundred (but it is always a multiple of four since representatives of this class of animals are characterized by radial symmetry).
Their tentacles consist of their line cells, which contain poison, and therefore are directly intended for hunting. Interestingly, even after their death, they can sting for a month. Some species can be deadly dangerous even for humans. For example, an animal is known as the «Sea Wasp» is considered the most dangerous poisonous animal of the world’s oceans: scientists claim that its venom is strong enough to make sixty people sick in a few minutes.
The outer part of the body is smooth and convex, while the lower part resembles a sack. In the center of the lower part is the mouth: in some jellyfish, it looks like a tube, in others, it is short and wide, sometimes it resembles short maces. This hole also serves to remove food debris.
These animals grow throughout their life, and their size largely depends on the species: among them, there are very small, not more than a few millimeters, and there are also huge ones, whose body size exceeds two meters, and together with the tentacles — about three meters. For example, the largest jelly of the world ocean, Cyanea, which lives in the North-West Atlantic, has a body size of more than 2 m, and with tentacles, it is almost forty meters.
Despite the fact that these marine animals do not have brains and sensory organs, they have photosensitive cells that play the role of eyes, thanks to which these organisms are able to distinguish darkness from light. Interestingly, some specimens glow in the dark, while species living at great depths have red color and those that live closer to the surface emit light.
Another interesting feature of these creatures is their ability to restore lost parts of the body — absolutely all cells of these animals are interchangeable: even if this animal is divided into parts, it will restore them, thus forming two new individuals! If this is done with an adult one, an adult copy will appear.
Since all representatives of this class (even the largest individuals, whose weight exceeds several dozens) are almost unable to resist sea currents, scientists consider jellyfish as representatives of plankton.
Most species do not give in to the water currents, and although slowly, they move, using the current and the thin muscle fibers of their body: cutting, they fold the body of a jellyfish like an umbrella — and the water that is in the lower part of the animal is pushed outward.
As a result, a strong jet is formed pushing the animal forward. Therefore, these sea creatures always move in the direction opposite to the mouth.
These amazing animals are the most numerous predators on our planet. They feed mainly on plankton: fry, small crustaceans, fish caviar. Larger specimens often catch small fish and smaller relatives.
They hunt with the help of stringent tentacles, which, after catching a touch of edible food, instantly inject into it venom that paralyzes the victim, after which the jellyfish eats it. There are two more options for catching food (much depends on the type of jelly): the first — prey sticks to the tentacles, the second — gets entangled in them.
What does Jellyfish Day mean will be described now. To some extent, this day doesn’t refer to holidays and more to mourning days, which give us a statistics about a number of deaths each year caused by these animals. Nevertheless, many countries organize parties when International Jellyfish Day 2017 is. For example, lots of competitions are held to definite who will eat more fish. There are a lot of awards for such events and crazy emotions are guaranteed.
For better understanding, we want you to get acquainted with one interesting fact in the order you have already known what is the date of Jellyfish Day 2017. The most venomous one in the world belongs to cubomedusae species, it lives near the Australian coast and is called the Medusa-box or the Sea-Wasp: its venom is capable of killing a person in just a few minutes. The ‘wasp’ is almost transparent, pale blue, which makes it hard to notice on the water, which means it’s easier to stumble upon it.
Simply saying, there are no traditions in the world associated with the date when is National Jellyfish Day 2017, no calendars show detailed info on it. Nevertheless, if you want to find some it’s recommended to refer to Australia and find out some interesting traditions and notes.
National Jellyfish Day Facts
- It is believed that jellyfish as a species appeared over 600 million years ago, long before dinosaurs, crocodiles, and sharks.
- Turritopsis are theoretically immortal. Reaching maturity, such a jellyfish can sink to the bottom and turn into a polyp. Then the polyp again develops into a jellyfish — and so on ad infinitum. True, this is possible only in laboratory conditions, since in nature jellyfish of this type are eaten earlier than they manage to be reborn.
- In the Republic of Palau, in the eastern part of the island of Eil Malk, there is the Lake of Medusa. In this pond, measuring 460×160 m, there live about 2 million jellyfish of various species.
Thereby, always keep your eyes peeled and keep in touch with everything surrounding your family and you.