The oceans are home to a countless number of animal species, among which we find the cnidarians, some fascinating and beautiful animals. They include the class Scyphozoa, which corresponds to one of the most striking types of jellyfish and does not usually represent any danger to humans. In this tab of our site we introduce you to a member of the Scyphozoa class, commonly known, due to its peculiar appearance, as fried egg jellyfish or Mediterranean jellyfishWe invite you to continue reading to learn more about this beautiful and peculiar animal.
Features of the jellyfish fried egg
The scientific name for the fried egg jellyfish is Cotylorhiza tuberculata. It is a small-medium-sized animal that measures between 20 and 40 cm, although its umbrella can reach up to 25 cm in diameter. This last structure is quite particular in this animal, since, observed from above, is similar to a fried egg Thus, it is rounded, cream-colored and with the center bulging and brown or reddish in color.
It has sensory organs and eight oral arms from which various branches emerge that form the tentacles. It is bordered with knobs in the form of buttons with different colors, such as purple, white or blue, which makes it even more eye-catching. Beneath these structures, the coloration can vary from greenish, to brown or orange, depending on the algae that live associated with it.
The body is essentially gelatinous and its tentacles are loaded with a toxic substance that is not dangerous to humans. In case of contact, it only causes mild to moderate irritation, depending on the person's sensitivity. A remarkable characteristic of this cnidarian is its sexual dimorphism: the females have filaments where they will house the embryos while they develop after fertilization.
Fried Egg Jellyfish Habitat
The habitat of the fried egg jellyfish is in the waters of the Mediterranean Sea, so it lives near the coastline of countries like Spain, France, Italy or Greece, among others. Depending on the time of year, it is found near the coast or moves to open sea areas. In addition, in one of its reproductive phases it moves to shallow waters with a rocky bottom. This jellyfish has also been observed in the Mar Menor, in the Aegean and in the Adriatic. Large numbers of specimens tend to accumulate in closed maritime areas that are used for tourist activities, which generates certain inconveniences for people.
Fried Egg Jellyfish Customs
This is a jellyfish that lives mainly in surface waters, however, it also moves to certain depths. Although it can be carried away by water currents, it is capable of swimming on its own, moving both vertically, for which it contracts and expands the body, and horizontally, achieving a deep dive.
If the surface water has a lot of movement, it tends to submerge to settle in calmer areas. It is common for large aggregations of individuals to form along the coastline at the end of the summer and autumn, coinciding with the time when the beaches are used by the people. When the water begins to cool down, with the arrival of the winter season, the fried egg jellyfish moves towards open water in the high seas. On the other hand, it is common for it to be surrounded by certain species of fish, which are not affected by its toxicity, which take refuge in its arms to avoid its predators.
Feeding the jellyfish fried egg
The fried egg jellyfish has two forms or types of food. One is through the capture of small fish, and even other smaller jellyfish, which it traps and inoculates poison using its nematocysts. This substance causes the prey to freeze, allowing the jellyfish to slowly devour it. It also feeds on marine plankton It does not show a very varied diet in terms of the consumption of these microorganisms.
The other way of feeding the Mediterranean jellyfish is through the symbiotic relationship that it establishes with certain algae, specifically dinoflagellates photosyntheticThe jellyfish provides a place where these single-celled forms can dwell. In exchange, they, from their photosynthetic action, store energy after fixing macromolecules that are used by the jellyfish, thus obtaining an important source of nutrition that influences their development.
Reproduction of the fried egg jellyfish
The reproduction of the fried egg jellyfish is like that of other cnidarians, having a sexual and an asexual phase The sexual phase is divided in four stages, which occur in an annual cycle. Summer is when the largest population growth occurs. Sexually differentiated jellyfish mature in the summer and the adult females fertilize themselves internally with sperm released by the male in a process that tends to occur between August and October. Subsequently, the planulae develop and, once gestation is complete, a large number of them are released into the water, where they move to rocky bottoms to settle and go on to a sessile lifetime
The planula adheres to the substrate to generate the polyp and it is at this stage that the symbiosis with the algae begins, which will last the rest of its life. Here the asexual reproductive phase occurs, so that the polyp forms others identical to it in this way and, eventually, metamorphoses to give rise to the ephyras, which will be released between spring and summer, finally transforming into the free-living jellyfish.
Conservation status of the fried egg jellyfish
The fried egg jellyfish is not considered to be at risk of decreasing its population levels, in fact, it is not included in the red list of the International Union for Conservation of Nature. On the contrary, this animal has been having high growth rates in summer times, accumulating in large numbers in coastal areas.
This has led to the use of fishing nets to try to contain their passage and avoid contact with bathers in the most touristic areas. The growth has been such that in a single year up to five tons of this jellyfish have been collected. Although, as we have mentioned, it does not have a lethal poison for people, it can cause some discomfort in sensitive individuals.
