Virtual reality fish. Designer creating a virtual reality Porcupine fish, Diodon hystrix, using a computer aided-design (CAD) package. This is one of 24 species of sea life constructed on computer with realistic behaviour. These were added to a virtual model of the Lisbon Oceanarium in Portugal, the largest aquarium in Europe. The virtual Oceanarium is part of Expo 98, which is themed around the oceans. A supercomputer simulates the interacting sea life in the Oceanarium's ocean habitats for the visitors to view in three-dimensions. Photographed at the Fraunhofer Institute for Computer Graphics in Darmstadt, Germany, where the model was developed.