Mediterranean jellyfish

Meduse del Mediterraneo Mediterranean jellyfish Cnidari cnidarian

Mediterranean jellyfish are marine planktonic animals, belonging to the phylum Cnidaria, which together with the Ctenophores formed once those who were Coelenterates. We publish a collage of several jellyfish encountered during our dives.

Pelagia Noctiluca has a direct development, without any polypoid stage, pink, reddish or purple, has an umbrella of about 10 cm in diameter and tentacles, eight in all, which can touch the meter in length. Its venom is very stinging also to humans, in fact Pelagia is the species that provides more irritation to swimmers. Sometimes in the dark it emits a green light.

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Rhizostoma pulmo or Barrel Jellyfish. Certainly for size the largest in the Mediterranean. It can weigh up to 9 kg. The sea lung can reach and exceed 50 cm in diameter. The umbrella has 80 lobes. From whitish color with blue edge lights. Despite the size of the lung is harmless sea and swim next to it is a truly fascinating. Often it hosts among its numerous tentacles fish, as the fish fry such Trachurus, Boops and Seriola.

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We think we have also encountered the jellyfish Aequorea forskalea is a part of the Aequoreidae family. From the typical form, which characterizes every jellyfish, this species has the top aptly named umbrella (for the familiar shape that has) long about 8-25 cm in diameter, from here radiate different brown radial channels or dark blue, the which are directed by the umbrella edges into the stomach. Has many tentacles, long and thin, the texture and coloring are typically transparent and gelatinous, since they formed more water.

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Cothyloriza tuberculate or Jellyfish Cassiopeia The shape of cassiopea resembles a flying saucer. The umbrella is depressed and convex at the center. The margin is typically jagged. Eight-branched arms, short tentacles that end with blue-purple disks. The brown color is due to the presence of microscopic algae called zooxanthellae. It probably feeds on small planktonic animals. It almost always accompanied by young fish of the genus Trachurus, which in case of danger, they flee among the tentacles of jellyfish. The cassiopea is harmless. It prefers warmer waters of southern Italy.

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Velella velella, sea raft, by-the-wind sailor, purple sail, little sail, is a colony of hydrozoans of the Porpitidae family. It is often found in all oceans, on the banks or at most 1-2 cm deep in the water, with a preference for warm or temperate waters.

Like other cnidarians (coelenterates), Velella velella is a carnivorous animal. It captures its prey, generally plankton, through the tentacles that contain toxins. These toxins, although effective against prey, are harmless to humans, since they cannot penetrate the skin and do not cause any reaction to human skin.

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Olindias phosphorica is a species of jellyfish originating from the central Atlantic, and from the Mediterranean Sea, including Malta.

Olindias phosphorica is a small hydromedusa whose hemispherical umbrella can reach six centimeters in diameter. The umbrella, sometimes flattened in the disc, is totally translucent by day. At night, when the animal will be more easily observable, it has a bioluminescence which gives it a blue-green hue.

The jellyfish has four main radial channels arranged in a cross, pink-red or mauve, and along which the gonads extend, emerald and white in color. The latter sometimes extends to the lips of the handlebar, elongated and ends in a narrow mouth.

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Ref.: http://www.ilgiornaledeimarinai.it/meduse-mediterraneo/