Thicktail Chub The Thicktail Chub was a small freshwater fish that inhabited the lowlands and weedy backwaters of Sacramento and San Joaquin rivers in California. The Thicktail chub was one of the most common fish in California and in fact constituted approximately 40 percent of the fish population in Sacramento river. Thicktail Chubs extinction was triggered by habitat loss due to the conversion of a large part of land in Central Valley for agricultural use. Dam building, water diversion and other such agricultural projects led to a decline in the fish population. Further more competition with exotic species and hybridization blurred the chances of recovery and the Thicktail Chub became extinct in late 1950s.
