Jellyfish have been around for millions of years and live in many different ocean habitats. Many jellies are clear and see-through, but they can also come in many different colours and some are bioluminescent, which means they can produce their own light.
Jellyfish are very interesting. They are made up of mostly water (95%) and consist of Mesoglea, which is a translucent jell like substance and there are so many different species of jellyfish. The jellyfish has an umbrella, a mouth (which is also the butt, the eat and poop out of the same place!), and tentacles.
A swarm of jellyfish is called a bloom.
A lot of jellyfish are harmless but many can still harm you. They sting you by brushing their tentacles against you. Then they discharge their venom into your skin by injecting instantly.
Cassiopea (upside down jellyfish):
The Cassiopea produces mucus with dispersed stinging cells, and when it touches your skin, it can cause irritations.
It is mostly found on the sandy ocean floor, but it can found on rocks aswell.
The Cassiopea has a distinct look, its unbrella is against the floor, whereas the mouth and tentacles are upwards. because of this, the species is called the upside down jellyfish.
This is a very harmful jelly due to the venom. If it stings you, it can be extremely painful and can cause scars to be left on your skin. It has stung a enormous amount of people in the Mediterranean and most jelly stings there are from this jellyfish.
During the summer, you can find a bloom of Pelagia noctiluca in the sea, which often disturbs people on their holidays.
The jellfish is restricted when it comes to movement however. Only being able to move vertically makes them rely on the currents and this causes them to travel in blooms.
The mouth has four long oral arms, the colour of the whole jelly is mauve, that is how it obtained the name ‘mauve stinger’. The umbrella is also patterned with small dots.
The venom of this jelly is harmless for people when contact is made however, like all jelly’s, they are very delicate and can easily be damaged. In China, people eat these jellys due to them being harmless.
The are four white circles (gonads) visible through the bell of the jelly which make it easy to identify. The moon jelly has four long oral arms. These jelly’s are common in aquariums and due to the transparency, they change colour with the surrounding light.