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Jellyfishes evolved 600 million years ago and since then never changed beacause they were already perfect. They appear and disappear without a reason. They easily adapt, they are mysterious and there are hundreds of beautiful species. They look beautiful

Jellyfishes are amongst the most prehistoric animals that still inhabit the planet today!! They were alive previoulsly to what paleontologists define as the ‘ Cambrian explosion’ when suddenly in the fossil fuel rests the ancestors of all living animals are found. Before that indeed in the fossil records are found either animals without descendants or Jellyfish. Almost the same to the current ones ! Which means that half a billion years of natural selection has not made them change !! Today they are back and everyone is wondering why…..

All over the planet fishermen instead of catching fish catch up jellyfish!!!! Everywhere swimmers instead of feeling at ease in a warm sea, are caught up by painful stings. Therefore, surprised they ask themselves what should be done Jellyfish appear in large quantities and suddenly disappear for a long time. This is innate in their nature!

Many species have an alternative kind of life as they spend most of their times at the bottom acting as polyps. Polyps and not octopuses Polyps resemble small corals, or hydra and stay attached to the bottom. Polyps can live decades without producing Jelllyfish but then thanks to a quick asexual multiplication they may produce many of them. On one day there isn’t even one of them but next day you may find billions…..!!!! If they find enough food and favorable currents jellyfish become like swarms ( like the one that a few years ago killed salmons from Ireland). A swarm that can be 14 km long and 5 km wide.

Why are there more and more jellyfish in the world ?? It looks like a planet phenomenon Jellyfish represent a global trend, a sum of occasional observations; we are witnessing a demographic boom !!!!

At the same time the climate is getting warmer and warmer and the number of fishes is decreasing. In two words: the climate is getting warmer and there are by far fewer and fewer fish. Is there a link between these last two statements and the increase in the numbr of jellyfish?

There are hundreds of different species of Medusa: from those of a few millimeters to the gigantic ones that can have an umbrella of three meters in diameter. Moreover, they live in all seas, under all conditions and can stay at the surface as well as in the abyssal depths. If global warming has an impact of jellyfish concentrations tropical ones would increase and those from cold waters decrease. Instead they are all increasing both in the heat as well as in the cold.

Jellyfish eat eggs, fish larvae and small crustaceans that make up the diet of numerous fish larvae. They are therefore predators and fish competitors at the same time.

Many fish, on the other hand, eat jellyfish and their larvae, which in turn are competitors of jellyfish as they feed in the same way: plankton crustaceans. If predators and competitors over a certain kind of food are removed, the rest increase in number. Overfishing is likely to result in a boost in the number of jellyfish

Whether you are underwater, on a boat a ferry or a beach OBSERVE them and if you happen to have a camera or sharp eyes detect them, fill in the apposite form and send your report!!!

Now you are aware of which ones are dangerous and which ones may be approached without fear…… If you see them write us Each observation will add an extra pin on the map making us understand the effect of this phenomenon. Science seeks your support !!

Prof. Ferdinando Boero, Marevivo Vicepresident

The most important species

The most admired specie of the recent years is Pelagia Noctiluca

Pelagia develops immediately without going through polyp stage. It is pink and reddish is provided with a 10cm ubmbrella in diameter, sometimes with whitish spots, long mouth arms and long tentacles at the edge of the umbrella…. If you happen to be stinged it is painful !! Pelagiastings and hurts feeling like a burn. A few years ago Pelagia stung 60,000 people in Spain and devastated salmon waterculture from Ireland. If in the sea numerous jellyfish are found they are more likely to be Pelagia Noctiluca.

The largest medusa in the Mediterranean is Rhizostoma pulmo and is nicknamed lung of the sea. It can easily exceed half a meter in diameter. It is generally whitish with a blue border. Sometimes it is just blue She is big with a handlebar that hangs from the center of the umbrella. She looks beautiful and does not sting.

Another harmless jellyfish is Cotylorhiza tuberculata yellowish with an umbrella between 10-20 cm, short and colored tentacles looking like a flower bouquet!

Chrysaora hysoscella almost looks like Pelagia but you can’t be mistaken …..the umbrella looks like a wagon wheel. Like Pelagia she has long mouth arms and tentacles. She also stings and hurts

Aurelia Aurita is harmless, her umbrella is half a meter of diameter, but she is usually smaller. She is almost flat and in transparency four well defined circles can be seen.

Aurelia Aurita is harmless, her umbrella is half a meter of diameter, but she is usually smaller. She is flat and in transparency in her umbrella four well-defined circles are seen. Carybdea marsupialis is a killer jellyfish found in Australia and like Chironex fleckeri can kill an adult man in a few minutes. Carybdea is not at this level but may still hurt very much. The umbrella is cubic, of a few centimeters (Cubozoa group, cubomeduse) and has 4 tentacles. The group to which it belongs is the Cuboza. It cannot be seen ……but it can hurt In our waters she is becoming common. Aurelia Aurita is harmless, her umbrella is also half a meter of diameter, but she is usually smaller. She is almost flat and in transparency four well defined circles can be seen.

Olindias phosphorica is increasing along our coasts…. She behaves in a particular way swimming with energy towards the surface and once it reaches the surface opens its tentacles and slowly descends to approach the bottom. During the descent it captures the smaller crustaceans and eats them. Once at the bottom it rises upwards. Swimmers have the impression that they are waiting at the bottom for someone to sting. It does not hurt like Pelagia but meeting her is not a pleasure. The umbrella measures up to 5 centimeters and has 4 red and yellow lines that go from the center to the periphery, surrounded by red dots, from which many tentacles start.

Illustrazioni di Alberto Gennari

a hot report

If a jellyfish stings you, wash the area immediately and repeatedly with sea waters and gently remove the residues of the tentacles. Avoid scathcing, rubbing with sand, using ammonia, vinegar, alcohol or lemon juice.

If you to a seaside emergency room, you will also help research in this way. The seaside emergency rooms indeed record all cases. From accurate recordings they come up with statistics concerning human health during the summer period. If you self heal or go to a pharmacy, your sting will not be considered by statistics..

The Occhio alla Medusa campaign.

To keep the phenomenon of the proliferation of jellyfish under control and in order to understand what is going on at Mediterranean level, the International Commission for Scientific exploration of the Mediterranean sea (CIESM), in collaboration with Marevivo has set up a network of observatories on jellyfish, involving both the scientific community as well as ‘casual’ observers who, from a beach or a ferry can turn into precious jellyfish lookouts.

We have seen that jellyfish can suddenly arrive and suddenly disappear. Hardly ever is this scientifically recorded Marine biologists are not in the position to depict the situation precisely.

Jellyfish are visible, especially the bigger ones and the ones directly linked to humans can be easily identified. Each and every one of us mey report their observation. Perhaps sending a digital photo even if taken using a mobile phone.

Download the poster that shows the main species and send the relevant informations to the coordinators of ‘operation jellyfish’

All informations shall be collected in a database that will alllow you to know where jellyfish are most numerous. Each sighting should contain relevant informations on the kind of specie and their frequency. a digital photo would be of great support.

Let us know if you observe :

  1. isolated species(their proliferation can be sudden; from one to many !!! )
  2. Numerous species are apart from one another in the open sea
  3. Or grouped in strips due to currents (Langmuir) which gather garbage as well as plankton in strips.
  4. clusters of jellyfish and then form swarms might form
  5. numerous species are driven by wind along coasts or close to harbors (these events occur at the end of the life cycle, when the jellyfish release the gametes and form the larvae and then the polyps).
  6. beached jellyfish