“When I first saw one, I couldn’t believe it. I didn’t think you could see one in a lake. We decided to put one in a transparent glass so we could see it better. ‘Observe’.” Together with his sister and his mother, Ilya made an amazing discovery a few days ago in the lake of Saint-Cassien.
Bathing there, as he usually does, the 12-year-old from Grasse faced jellyfish swimming between two bodies of water. The jellyfish of Lake Saint-Cassien are much smaller than those found in the sea or on our shores. They are translucent and only about two centimeters in diameter.
“Not the first time”
On the Maison du Lac side, we are not surprised to learn of the presence of jellyfish. “It’s been a few years since the presence of these animals was reported to us on an ad hoc basis,” explain the members of this tourist office in the Pays de Fayence. This year we have not had any feedback on their attendance. There is no certainty as to how this species got into the lake. There are several theories. One thing is certain: in order for this animal to be observed, special conditions are required. The water has to be warm.” This is exactly what is currently happening in Lake Saint-Cassien.
Present on all continents
Fine connoisseurs of the life of the flora and fauna of the lake, the fishermen list the living species. Grégory Bertin, director of leisure development at the departmental fishing association, was contacted by Var-matin and provided us with an identity card for the little beast. Reading the document, we learn that the freshwater jellyfish is also called Craspedacusta sowerbyi. It is found on every continent on earth, although its original origin is believed to be European. It was first observed and described in England in the late 19th century and prefers standing water to torrents.
No risk of stabbing
Like sea jellyfish, it has no skeleton. On the other hand, it can count a great many narrow and grouped tentacles. It is translucent (sometimes whitish in color), slightly flattened, and feeds on zooplankton. Its presence from one year to the next is neither guaranteed nor predictable. On the other hand, a high temperature increases the likelihood of development. Finally, they don’t burn. May the bathers of the lake rest easy.