Nature Reserve

Portofino, a World apart
November 2017

Pelagia noctiluca (Medusa Luminosa)

Pelagia noctiluca is a jellyfish in the family Pelagiidae.It is a beautiful jellyfish, very itching, with eight long filaments (retractable tentacles) that can cause painful burns to the bathers. In the depths of Portofino, it’s quite a common sight, especially when exploring the submerged rocky base beneath the Lighthouse. This area boasts countless nooks and crannies, revealing an incredibly diverse ecosystem. Its coloration is very varied, with often spotted maculature but sometimes even lighter color. Pretty big, it has an umbrella that can reach 20-25 centimeters in diameter, and tentacles that lie out can be long over two meters.

This type of jellyfish is very welcome from the turtles Caretta Caretta, Moon Fish (Mola mola), or even fish like the Boghe (Boops boops). These last ones usually bite them at a time when, after days of storming, they come under the coast losing much of their creeping power.

The Pelagia noctiluca captures organisms from the plankton such as eggs and larvae, young fish, and copepod crustaceans. It is called a bright jellyfish because it manages to produce light at night but only when approaching it by stimulating it, perhaps by increasing the pressure in the water.

It is a jellyfish that, unlike other Scyphozoa, does not have the polyploid phase and, after coupling, produces eggs that originate directly from new jellyfish, which develop without having any contact with the backdrop.

Please be careful if you find a Pelagia noctiluca on your way. Thanks to Dr. Giorgio Massa, Biologist. Dr. Gabriella Motta, Photographer.

Portofino, what else? 🐬