Home pageAquariumUnusual residents

Unusual residents

The population of the Aquarium is constituted of species living in the north-western Mediterranean, most of them frequent in the waters around the island of Les Embiez. But the scientists also run into less common species, some of which conserve their aura of mystery.

Psenes pellucidus
Psenes pellucidus
Epinephelus caninus
Epinephelus caninus
Epinephelus merra
Epinephelus merra

This fish habitually lives in the temperate or warm waters of the Atlantic, the Pacific and the Indian Ocean. Very rare in the Mediterranean, it is an invasive species coming in from the Atlantic via the Strait of Gibraltar; it has not been reported along the southern coasts (Algeria, Morocco, Balearics).

The young live in the open sea, often beneath floating objects, and the adults near the bottom down to 1000 m depth.

Fifteen or so individuals were caught in the port of Le Brusc (near Toulon, S.E. France) in December 1995 among a shoal of jellyfish Pelagia noctiluca, and another specimen in the same place, under similar circumstances, in October 2009.

The grey or dogtooth grouper lives in the eastern Atlantic and in the Mediterranean. It is extremely rare off the French coasts, where only a few sightings have been reported in Corsica and only one at Cassis (near Marseille) in 1996. A local restaurant owner presented the Aquarium at Les Embiez with a specimen of a grey grouper that he had conserved in a live tank and which had been caught two years previously by a professional fisherman at Cassis.

The honeycomb grouper or dwarf spotted rock cod habitually lives in the Indo-Pacific, from South Africa to French Polynesia. It is unknown in the Red Sea and in the Persian Gulf, and a fortiori in the Atlantic and the Mediterranean.

However, in September 2004, fishers at Le Brusc (near Toulon, S-E France) caught in their nets off the island of Les Embiez a fish they did not recognise; they presented it to the Paul Ricard Oceanographic Institute Aquarium. The grouper was injured and did not survive being caught.

Scientists identified this species as being completely unknown in the Mediterranean: Epinephelus merra. Its size of about twenty centimetres indicated that it was an adult. The autopsy showed that it was a female and the large amount of fat surrounding the digestive tube was characteristic of individuals that have lived in captivity.

How did this fish get there ? The hypothesis of passage through the Suez Canal or the Strait of Gibraltar can be ruled out since it had never been found it either the Red Sea or in the Atlantic.

The likeliest explanation is voluntary or involuntary release from a tropical marine aquarium, but the public aquariums nearby do not exhibit this species. The only remaining possibility is release from a private aquarium, but Epinephelus merra is not offered for sale by the main importers of exotic fishes.