Reflections from the Ocean Floor. Leopold Blaschka's Marine Aquaria. The paper focuses on the glass models of marine invertebrates by Leopold Blaschka (1822–1895). In the beginning of his career, Blaschka did not produce stand‐alone scientific models. Instead, he chose to create “marine aquaria”, i.e. dry fish tanks filled with artificial sea creatures, to promote and present his glass objects to the public. This concept was clearly inspired by the work of the British naturalist Philip Henry Gosse (1810–1888). By describing the influence of Gosse's work, the paper argues that the aquarium served as a tool to display and organize Blaschka's early models.