In this article the author presents a report on the high-performance computer simulation through the so called Virtual Oceanarium model of the Lisbon Oceanarium of Portugal which is claimed as the largest aquarium in Europe. The aquarium was built during the World Fair Expo in 1998 in Portugal. Since then, there has been a rapid growth of human visitors to this Oceanarium. It is described that the computer simulation done here provides an opportunities to visitors to interact with 25 species and about 1,000 individual creatures and plants and may understand their typical behavior. A simulated graphical structure of the Oceanarium is provided here to show its content and components' structure. The author describes that its core component is a real-time simulation system for producing artificial creatures designed to meet the audience's expectations, running a constantly high frame rate and presenting a detailed virtual environment. The software's modularity makes it possible to readily integrate new species and new behaviors; moreover, the models of the aquarium and its fish tanks can be modified or exchanged, and models of real-world coastlines can be added as needed.