Identifying the drainage of origin of leatherside chub found in the Colorado River system

Authors: Adam Q. Barrager, Jerald B. Johnson

Year: 2010 (xlii)

Abstract

What was once considered to be a single species of leatherside chub is now recognized as two distinct species: northern leatherside chub (Lepidomeda copei) found in the upper Snake River drainage and southern leatherside chub (L. aliciae) found in the Sevier River and Utah Lake drainages of the Bonneville Basin. These species are not known to naturally occur outside of these drainages. Recently, Utah Division of Wildlife Resource personnel discovered leatherside chub in the Fremont River of the Colorado River system. This discovery is of interest given conservation concerns about both leatherside chub species. Whether this is a native population or an introduced population remains unknown. In this study we used molecular genetic markers to determine if leatherside chub in the Fremont River have been introduced, and if so, what the source of that introduction was. We found that fish from the Fremont River are southern leatherside chub and that they are most likely introduced from the Sevier River system, with strongest affinities to populations found in the East Fork of the Sevier River. This is not surprising given the proximity of the East Fork of the Sevier River to the Fremont River and the historic widespread use of leatherside chub as bait minnows for recreational fishing.