Ecological Risk Screening Summary - Japanese Medaka (Oryzias latipes) - Uncertain Risk

Species that are considered uncertain risk need a more in-depth assessment beyond the Risk Summary to better define the species’ risk to U.S. environments.

Japanese Medaka, Oryzias latipes, is a minnow species native to Eastern Asia and is present in the aquarium industry. In the past it was used as a biocontrol for mosquitos and other vector insects. O. latipes may also be used in research. This species can tolerate a wide range of salinities and it is recommended to use diluted seawater in captive cultivation of the species. The history of invasiveness is Data Deficient. Oryzias latipes has been introduced outside of its’ native range; however, no information has been found on impacts from the introductions. The overall climate match for the contiguous United States was high. The entire contiguous United States had a medium to high match with the exception of the West Coast, in the Pacific Northwest, Rocky Mountains, and interior New England. The certainty of assessment is low due to lack of information of impact of introductions. The overall risk assessment category for Oryzias latipes is uncertain.