The Mediterranean Sea is one of the most studied marine environments in the world (from many points of view) because it has interacted with humans and their activities for thousands of years. This notwithstanding, it is still unsatisfactorily known from the biological point of view, and pelagic communities are the least known and studied among all. The Biological components of the pelagic Mediterranean are not drastically different from those thriving elsewhere, and ecosystem functioning is based on common rules. This notwithstanding, a precise reference to Mediterranean species and their existence is proposed here as a paradigm of other nonoceanic situations.