At the Mediterranean Sea there is a prodigious biological diversity, with a high degree of closely linked endemism. Unfortunately, in the early XXI century, many species are in a state of great imbalance due to incessant human pressure, pollution and overfishing.
Although we know the basics of more than the 15.000 animal species that live in the Mediterranean Sea, we ignore the natural behaviour of the most common ones, because many of them begin their activity after dark.