Isao Ijima (飯島魁, Iijma Isao; July 24, 1861 – March 14, 1921) was a Japanese zoologist known for his studies of sponges (Porifera) — including his circumscription of the genus Staurocalyptus — leeches (Hirudinea), flatworms (Turbellaria), birds, and fish. Professor of Zoology at Tokyo Imperial University, he is considered the founder of parasitology in Japan and was the first President of the Ornithological Society of Japan. Taxa named in his honour include Ijima's sea snake and Ijima's leaf warbler.
Source: “Isao Ijima”, English Wikipedia (CC BY-SA 4.0), excerpt