Jellyfish are generally marine animals that, like anemones or corals, are part of the cnidarians (a phylum that groups around 10,000 species of more or less simple animals, living exclusively in aquatic environments).
Cnidarians are one of the oldest animals that inhabit the Earth , since they appeared 600 million years ago. They are characterized by the presence of cells called cnidocytes, which have stinging organelles. Despite having a simple structure and functionality, they inhabit almost all aquatic environments, mainly marine ones. There are two basic forms in the life cycle of a cnidarian: polyp , in which the animal is sedentary, with a tubular body, and reproduces asexually; and jellyfish , which can swim freely, shaped like a bell and reproduces sexually. There are organisms that are only one of these two stages, while others are initially polyps and then jellyfish.
The most unique thing about Mediterranean jellyfish is probably the speed with which they grow, with sizes ranging from a few millimeters to 100 centimeters, as is the case with the aquamarine jellyfish , one of the largest jellyfish that inhabit the Mediterranean Sea.
Mediterranean jellyfish are very special. There are some unusual looking ones, such as the fried egg jellyfish, which has a smooth, raised bell surrounded by a ring. It has numerous short appendages that expand and flatten at the ends, in addition to some longer ones. The clustered appendages contain mouth-arm openings that are deep purple in color.
This jellyfish barely lives for half a year , from summer to winter. The researchers believe that this short lifespan is the result of adaptation to a highly seasonal environment in which the water temperature varies greatly.
Massive blooms of the Mediterranean jellyfish appeared in the coastal lagoon of the Mar Menor in the Mediterranean area after human activities, including agriculture, caused nutrients to seep into the soil and eventually into the water across the coast.
Jellyfish populations flow naturally. Scientists are now wondering if human impacts such as overfishing, pollution and climate change could also affect jellyfish populations not only in the Mediterranean, but around the world.
Do you want to know the fantastic Mediterranean jellyfish? We started!
