Katsumi Tsukamoto (born 1948) is a Japanese ichthyologist and fisheries scientist. Professor Emeritus at the University of Tokyo, he specializes in the ecology, evolution, and conservation of migratory fishes, particularly eels. He is widely recognized for leading the research that identified the spawning area of the Japanese eel in the western Pacific. His best-known book, "Unagi: Ichioku Nen no Nazo o Ou" ("Eels: Pursuing a Hundred-Million-Year Mystery"), draws on decades of field research to explain the eel's remarkable life cycle, migratory behavior, and the scientific efforts to protect this endangered species.
