Recent, small beginnings: genetic analysis suggests Catostomus rimiculus (Klamath smallscale sucker) in the Smith River, California, are introduced.

Identification of introduced species can be important to understanding ecological systems and meeting conservation and management goals, but the process can be surprisingly challenging. The Klamath smallscale sucker Catostomus rimiculus seems likely to be native to the Smith River because the drainage separates two basins believed to be within the fish's native range, the Rogue and Klamath rivers. Further, C.

Small founding number and low genetic diversity in an introduced species exhibiting limited invasion success (speckled dace, Rhinichthys osculus).

Molecular evaluations of successful invaders are common, however studies of introduced species that have had limited invasion success, or have died out completely, are rare. We studied an introduced population of speckled dace (Rhinichthys osculus) from northern California, USA that has rapidly increased in abundance but remained restricted to a 25-km stretch of river since its introduction in the mid-1980s. Field and laboratory analyses indicate that invasion success of speckled dace is constrained by the combined effects of multiple predators.