A “hot air balloon” 40 meters deep? In any case, this is what the Calanques National Park describes on its website. Experts describe a “large transparent sphere” (GST) which was observed at the end of October off the coast of Marseille.

These GSTs are large, transparent, jelly-like pouches. They generally measure more than a meter in diameter. In their center is nestled a cord that contains thousands of squid eggs. These are visible as small white particles.

This “crystal ball” was 40 meters deep and was discovered by divers from Narval Plongée, reports the site.

The GSTs, which have aroused the curiosity of experts for several years, look a lot like “transparent bags” which contain “thousands of squid eggs”, explains a spokesperson for the Calanques National Park.

Delphine Thibault, working at the Mediterranean Institute of Oceanology, recalls that “conclusions concerning GSTs must be cautious insofar as scientific knowledge on squid reproduction remains fragmented”.

These findings are rare because GSTs usually drift at great depths and the spheres hatch only after two or three days. This is the 4th time in 10 years that this phenomenon has been observed near Marseille.

The Calanques National Park reminds divers that it is forbidden to take part of the GST. On the other hand, “taking macro photos and collecting data (size, depth, water temperature) are encouraged to advance knowledge”, he announces.