Ecological Risk Screening Summary - Large-scale Loach (Paramisgurnus dabryanus) - 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.

Paramisgurnus dabryanus, the Large-scale Loach, is a species of fish native to parts of Russia, mainland China, and Taiwan. It is present in the aquarium and aquaculture trade, as fish bait and for human consumption. P. dabryanus has been introduced and is established in Japan. No negative impacts of introduction have been reported. Within the contiguous United States, introductions have been reported in the Powder-Snake River drainage, Oregon (as Misgurnus mizolepis), and in the San Joaquin River, California. The introduction failed in Oregon, and the status of the introduction in the San Joaquin River is uncertain. History of invasiveness is classified as “none documented.” The climate match within the contiguous United States is high, with high matches occurring in the Southeast and Midwest, and low matches occurring in the West where previous introductions of P. dabryanus have occurred. Certainty of assessment is low because of the lack of information on impacts of introduction as well as the difficulty of distinguishing between this and related species on the basis of external morphological characteristics. The overall risk assessment category for P. dabryanus is uncertain.