This rocky area belongs to the municipality of Ras Jbal in Bizerte.



It is a species without stinging cells (cnidocytes), therefore it is completely harmless for the humans.


Salps are considered within the group of jellyfish due to their gelatinous consistency, nevertheless they are not Cnidarians but belong to the phylum Chordata.

In general, they are translucent organisms with a barrel-shaped body where the stomach can be clearly distinguished at one end of the body as a blue (in Thaliademocratica) or reddish-brown button (in several species, for example in Salpa fusiformis). They move using the contractions of their body when pumping water in and out.

They present a solitary life phase, known as oozooid, and an aggregate phase, where they form chains of individuals called blastozooids. The chains can reach up to 6 meters in length.


The most frequent species on the Catalan coast are Thaliademocratica and Salpa fusiformis, but it is also possible to find Salpa máxima or Pegea sp. Although their frequency is variable, they are usually abundant during the spring period, when many gelatinous organisms proliferate, and in autumn.

The population proliferation of these animals are sudden and can be maintained for weeks.

Distribution and Habitat

They are globally distributed species.

Salpa fusiformis can be found in all the seas of the world except in the Antarctic and in the Arctic. It can live from the surface to approximately 800 meters deep and makes daily migrations along the water column. It can form extensive aggregations that are sometimes transported near the coast through streams.

Thaliademocratica is cosmopolitan, from warmer waters, with a very similar distribution to Salpa fusiformis, although it is more typical of coastal waters and generally lives in the superficial layers of the water column.