The Naples Aquarium, founded in 1873, was the first aquarium opened to the public. This predominantly scientific aquarium houses Mediterranean flora and fauna, and the policy is to contribute to the preservation of the marine environment. Under the coordination of Flegra Bentivegna two approaches are used: 1) educational; and 2) scientific and practical. The aim of the educational policy is to make the public aware, through the distribution of scientific data and observations, of the decline in the marine environment. The exhibition of new specimens or plants in a small, traditional aquarium such as the Naples facility, attracts much public interest, particularly when endangered species are involved. Such occasions are thus used to alert the public to the importance of safeguarding the sea and its inhabitants. Cases in point are the tanks containing replicas of the Posidonia oceanica environment, and the tanks housing Corallium rubrum. These 'endangered' species, are still found in the Gulf of Naples and can be seen in the Aquarium. Illustrative material is available that describes the species and explains how they have become rare. The ongoing scientific-practical activities are devoted to safeguarding the marine turtle. The aim is to increase this population in the wild and to improve our scientific knowledge of these animals in order to protect them better. In 1983, the Naples Aquarium started a rehabilitation program whereby wounded Loggerhead Sea Turtles, Caretta caretta, from the Gulf of Naples are recovered, rehabilitated, and released. These turtles are commonly victims of maritime traffic, pollution, or are wounded by hooks or nets.Caretta caretta do not come into this area to reproduce. Very probably, the turtles enter the Gulf of Naples to graze, and they probably come from the east Mediterranean basin where numerous deposition sites are located. To verify this hypothesis Flegra Bentivegna began in October 1995 to track a rehabilitated sea turtle in the, Mediterranean Sea using satellite telemetry. Information such as location, dive duration, and water temperature will help to develop a conservation strategy for Caretta caretta. Last year, 17 specimens of Caretta carettawere maintained in the Aquarium prior to their release, and their growth rate and some parameters of respiratory behaviour were studied. Temperature was found to play a role in the growth of Caretta caretta. In fact, growth is almost zero at 13-17°C, while it increases at 22-27°C. Food requirement and conversion values were also maximum at 22-27°C. Therefore, it appears that optimal growth of Caretta caretta occurs at about 25°C. Flegra Bentivegna also demonstrated that temperature affects the voluntary dive duration of Caretta caretta when the animal is in captivity. With an increase in temperature the per cent duration time decreased. Between 22 and 27°C dives never lasted longer than 40 min. Between 13-17°C, dive duration increased, but was never longer than 120 min. These findings clearly show that the resistance of a diving sea turtle is lower in summer than in winter. Data on dive duration can be useful to evaluate the chances of survival of a sea turtle trapped in a net. Attempts have also been made to breed the sea horse in captivity. The two species, Hippocampus hippocampus and Hippocampus guttulatus, present in the Mediterranean, have gradually almost disappeared from the Italian coast, where they were once abundant. The main aim of this research, sponsored by Omega Seamaster, is to re-introduce reared sea horses into protected areas.