DNA tests confirm that the species is of a type not previously known to science.
By Zafrir Rinat
A hitherto unknown species of jellyfish has been sighted off Israel’s Mediterranean cost and is being studied by Israeli and Australian scientists. While the sting of the new visitor is less painful than that of the type of jellyfish that local bathers know all too well, its sighting is another worrisome sign of ecological problems in the Mediterranean.
The species, which has been given the name Marivagia stellata, is star-shaped, with a diameter of about 15 centimeters. “It is impossible to know for sure where it came from, but because we have not run into it before in our region, we assume it came from the Red Sea or the Indian Ocean,” Prof. Bella Galil, of the National Institute of Oceanography, Israel Oceanographic and Limnological Research, says.
Either way, the fact that it has been sighted on a number of beaches indicates that it has obtained a foothold in the area.
A dead specimen of the species was first found four years ago by an institute staffer on Haifa’s Bat Galim and brought to Galil’s laboratory. She sent it to Prof. Lisa-Ann Gershwin, a specialist in the field, in Australia, but to Galil’s chagrin the Israeli postal system lost the specimen.
But four months ago Meir Kadosh, a Haifa lifeguard, called Galil to report his find of an interesting creature that turned out to be from the same species.
A few weeks later, another specimen was found on the Beit Yannai beach. Gil Rilov, a colleague of Galil’s, photographed live specimens at Rosh Hanikra. This time, digital photographs were sent to Gershwin, along with DNA samples.
Gershwin was able to confirm that the species was previously unknown to science.
An article about the species in the scientific journal Acquatic Invasions thanks Kadosh and others for collecting the first specimens.
The presence of this and other invasive jellyfish species in the Mediterranean, including the familiar Rhopilema nomadica, concerns ecologists because they prey on the young of local fish species or consume the food those fish live on.
Two weeks ago Galil attended an urgent conference in Istanbul by the Mediterranean regional fishery management organization. Among the recommendations adopted was to encourage the development of local fish that prey on Marivagia and to increase monitoring of ships from the Red Sea that may be hosting the species.
However, failure to contain Rhopilema over the years does not bode well for dealing with the new species.
http://www.haaretz.com/print-edition/news/new-jellyfish-seen-as-evidence-of-troubled-local-waters-1.319441