The Barrel Jellyfish (Rhizostoma pulmo Macri, 1778) is one of the scifomedusa Rhizostomatidae family. Polmone di mare Rhizostoma pulmo scifomedusa intotheblue.it
Distribution and habitat
Detail of the handlebar and the tentacles of a Barrel Jellyfish. It is a pelagic species widespread in the ocean Eastern Atlantic, the Mediterranean Sea (frequently along the Adriatic and Ionian coast to coast, especially in late summer and early-autumn periods) and the Black Sea.
This jellyfish has a hemispherical shaped hat opalescent but tending to transparent, with blue-purple edges frayed. Below the hat the body is called the handlebar and is composed of 8 prolongations of curled and lumpy white-transparent fabric, from which depart 8 elongated tentacles, frayed and semitransparent. Young specimens tend to have a more transparent color, adults are much more opalescent. The common name of sea lung is due to the typical throbbing movement made by the jellyfish to move. The dimensions are worthy of note: being able to reach the 50-60 cm in diameter and 10 kg in weight, is the largest jellyfish in the Mediterranean.
The species does not cause serious consequences, its tentacles usually are not stinging posed a serious danger to humans. Only on sensitive people, the contact can cause irritation which disappear spontaneously in a short time but still leaving an annoying itching or pain. In water releases some stinging substance or toxin that causes small itchy and mild burning abrasions. The umbel, notoriously devoid of cnidocysts, it can still irritate sensitive parts such as the mouth (especially the lips) and nose. This is due to the release of irritants in the area immediately around the jellyfish, for defensive purposes. Irritations like that can cause swelling and numbness, but cured in a matter of hours.