The RBINS fish collection consists of more than 265,000 specimens. Oceanographer Gustave Gilson (director of the RBINS in 1909) started the collection during his study of the North Sea. It was the very first study of marine fauna in Belgium. The Institute has type material for 325 species. Central African fish species are well represented thanks to expeditions to the national parks in Congo. Missions by His Majesty Leopold III and RBINS biologist Jean-Pierre Gosse have also yielded many South American species.