The mesoparasitic copepod Lernaea cyprinacea Linnaeus, 1758 (Lernaeidae) was collected from me- daka, Oryzias latipes (Temminck and Schlegel, 1846) (Beloniformes: Adrianichthyidae), in a pond at Ago, Shima, Mie Prefecture, central Japan. Only fragmen- tary records existed of L. cyprinacea of Mie Prefec- ture, and the present collection represents the first specimen-based record of the species from the prefec- ture. Both a filamentous green alga Stigeoclonium sp. (Chaetophorales, Chlorophyceae) and peritrich ciliates were attached to the trunk of L. cyprinacea. Copepods were found to insert their anterior body into the host fish near the base of the pectoral, dorsal, and anal fins .