Blue Entrance

The creatures that best represent the evolution of our planet are those that have been able to adapt to the changes that have occurred. This tank holding 700,000 litres of water plays host to several shark species, including Sand Tiger Sharks and Nurse Sharks.

Interactions between the human species and the Chondrichthyes have always been characterized by competition and fear. Numerous species of cartilaginous fishes have often been caught by humans for thousands of years, without any signs of imbalance or overfishing being noted. This situation has changed radically over the last few decades due to simultaneous changes in three factors associated with the presence of humans in our planet’s seas and oceans:

1. increase of the human population;
2. technological developments in the field of fishing and navigation;
3. environmental degradation.

If therefore, on the one hand, the potential for attacks by Chondrichthyes against humans has remained unchanged or has even declined, due to a probable demographic decrease of several species, on the other hand, the harmful effects of human action on Chondrichthyes have dramatically increased.
There are many factors linked with the biology and ecology of cartilaginous fishes that make them particularly vulnerable to the negative effects of human action:

1. slowness of their growth;
2. long time taken by some species to reach sexual maturity;
3. low number of new-born young produced after a long period of gestation or incubation;
4. low replacement rate of populations, which in some species can be as low as 2% per year;
5. habit of many individuals of several species to gather together in conspicuous groups for reproductive reasons, thereby making themselves particularly vulnerable to overfishing;
6. presence of young in “nursery” areas susceptible to disturbance and degradation of the habitat;
7. position as predators at the top of the food chain, preventing many species from competing with humans.

Jellyfishes, mysterious and fascinating organisms that we never wish to meet, except when visiting an aquarium, are composed for 90% of water, and have a parachute-shaped body with a series of stinging tentacles with different lengths and shapes.

The first four windows show the lifecycle of the Moon Jellyfish, a jellyfish with a cosmopolitan distribution and very common in the Mediterranean. The moon jellyfish has a soft, gelatinous, cup-shaped umbrella, with an edge that appears fringed due to the presence of numerous short hollow tentacles.

Easily recognizable for the particular markings inside its body in the shape of a four-leaf clover, this jellyfish can reach diameters of up to 40 cm. In general they feed on small organisms captured with their stinging tentacles.

The last window shows the Cassiopea andromeda jellyfish, which has no stinging tentacles and lives resting on deep sandy seabeds, wandering silently without being able to defend itself. Watching it float suspended in the water is a striking experience.