SURVIVAL AND GROWTH RATES OF STOCKED RAZORBACK SUCKERS (XYRAUCHEN TEXANUS) IN A WETLAND OF THE GREEN RIVER, UTAH

摘要

We stocked four cohorts (larvae and juveniles) of razorback suckers (Xyrauchen texanus) into a managed floodplain wetland in the middle Green River, Utah, from 2008-2009. Our objectives were to determine razorback sucker early life stage survival and growth rates in a natural wetland setting. We used fyke, trammel, and dip nets in addition to boat electrofishing to address project objectives and to recover stocked fish from the wetland for translocation to the Green River. We released 1,515 razorback suckers from this wetland into the Green River, of which 110 (7.3%) have been detected in the river since stocking. Larval razorback suckers survived when few nonnative fish were present, but none survived when many were present. Juvenile fish had high mortality during summer months. We suggest fish and bird predation as plausible sources of mortality for razorback suckers in this wetland.