The slender chub (Erimystax cahni) is a species of ray-finned fish in the family Cyprinidae.It is found only in the United States, within the Clinch and Powell rivers.[1] It is likely extirpated from the Holston River, having last been observed there in 1941.[2] Due in part to a lack of targeted surveys, slender chub have not been definitively observed since the 1990s. The 2021 5-year review of this federally threatened species recommended environmental DNA sampling in future surveys with comparison to DNA extracted from preserved specimens.[2]