Jellyfish

  Jellyfish are primitive animals who have been living in the sea for 650 million years. They belong to the cnidarium phylum family (from the Greek Knide, meaning nettle), the same as corals or anemones. However, unlike these, jellyfish are pelagic organisms (they live in the water column) and form part of the plankton, i.e they move with the water currents. Due to this reason, jellyfish cannot follow us. They will just remain suspended in the water and float between the surface and a depth of about five metres, there where the light is brightest and the food abundant. If we go swimming with a diving mask and are specially careful, we will have the chance to observe these beautiful animals. Take care of not getting too close to them to avoid being stung by them (however, should the sea be filled with jellyfish, please do not get into the water).

Jellyfish are made up almost entirely (95%) of water and are a major source of food for certain animals, such as marine turtles (among the Mediterranean we will mainly find the sort Caretta caretta) and many types of fish. One of the main reasons for the higher population of jellyfish in our seas during the past few years has been the decline of these natural predators (tuna fish and turtles) due to an increased fishing activity.

Among the Mediterranean we will find the following types of jellyfish:

• Pelagia noctiluca 
• Cotylorhiza tuberculata
• Velella velella
• Rhizostoma pulmo
• Physalia physalis
• Aurelia aurita

Usually, the Pelagia noctiluca jellyfish, also known as "sea wasp", is the one responsible for most stings caused among our coastline.

Each sting requires a specific treatment, but there are some general steps that can be followed in case you are stung by a jellyfish:

1. Clean well the part of your body that has been stung by a jellyfish with sea water, without rubbing or scratching (immerse the affected part of your body in sea water and create water currents to remove any tentacle that may still be stuck to the skin). If these tentacles are tightly stuck to the skin, remove them with a rigid element (credit card, etc.), but never with your fingers.

2. After being stung, never ever clean the stung part of your body with sweet water. The urticant cells responsible for the itching react to non-salty water by expelling the harpoon, thus aggravating the condition and causing the pain. If there were still tentacles that had not yet been stimulated to expel the poison, they will do so with the change of salt-level in the water.

3. Apply cold during 15 minutes on the affected part of the body that has been stung. In case you use ice, please take into consideration that this is nothing else than sweet frozen water and as such, it should not touch the sting; use a plastic bag or similar to wrap around the ice.

4. Avoid being exposed to occasions that could favour any furhter jellyfish stings, since the risk of reaction is multiplied. In case you have already been stung once, please take special care to avoid being stung a further time.

5. In case of convulsions, heart or breathing alterations, please visit the closest hospital.