Ecological Risk Screening Summary - Owens Sucker (Catostomus fumeiventris)

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

Catostomus fumeiventris, Owens Sucker, is a fish native to the Owens Valley in eastern California, United States. C. fumeiventris has been introduced and become established outside of its native range along the margins of its native range and in the Santa Clara River basin north of Los Angeles. Most introductions have resulted from the transfer of water out of the Owens River via aqueduct. C. fumeiventris has been found to hybridize with Pantosteus santaanae in the
Santa Clara River, although the status of that P. santaanae population as native or introduced is uncertain. The History of Invasiveness for Catostomus fumeiventris is classified as Data Deficient because the species is established outside of its native range but no clear, convincing, reliable evidence of either negative impacts or lack of negative impacts was found. The climate matching analysis for the contiguous United States indicates establishment concern for this species outside its native range. The highest climate matches occurred in California, the Great Basin, and parts of the Pacific Northwest, Colorado Plateau, and Southwest regions. The Certainty of Assessment for this ERSS is classified as Low because of the lack of information regarding the history of invasiveness, including the uncertainty around the implications of hybridization with P. santaanae. The Overall Risk Assessment Category for Catostomus fumeiventris in the contiguous United States is Uncertain.