Investigations conducted by U.S. Department of the Interior agencies have documented elevated concentrations of selenium in water, sediment, and biota at various locations in the San Juan River basin. The San Juan River provides critical habitat for two endangered fishes, Colorado pikeminnow (Ptychocheilus lucius, formally named Colorado squawfish) and razorback sucker (Xyrauchen texanus) and concern has been raised about the effects of selenium on these native fishes. At present, little is known about the sensitivity of Colorado pikeminnow to long-term selenium exposures. The objective of this study was to determine the effects of dietary and waterborne selenium on survival, growth, and reproduction of adult Colorado pikeminnow under [...]