The reddish tuco-tuco (Ctenomys frater) is a species of rodent in the family Ctenomyidae. Five subspecies have been recognized, some formerly designated as separate species.[1] It is found in Argentina and Bolivia at altitudes from . This tuco-tuco is fossorial, like others in its genus. Its diet consists of underground tubers and roots. Its karyotype has 2n = 52 and FN = 78.[2]
It lives in colonies in areas with suitably soft, dry soil. Both undisturbed and disturbed areas provide suitable habitat. Its conservation status is assessed as "Least Concern" by the IUCN.