 By the 1990s, only three species of sport fish were left to support the once multispecies fishery, two of which were invasive.More recent research has suggested that remaining cichlids are recovering due to the recent surge in Nile perch commercial fishing, and the cichlids that are left have the greatest phenotypic plasticity and are able to react to environmental changes quickly.The introduction of the rainbow trout ("Oncorhynchus mykiss") in the late 19th century resulted in the extinction of the yellowfin cutthroat trout ("Oncorhynchus clarkii macdonaldi") found only in the Twin Lakes of Colorado, USA.