Towards conservation of razorback sucker Xyrauchen texanus one population at a time

Authors: Brian* Kesner, Chase Ehlo, Carol Pacey, Jamie Wisenall, Paul Marsh

Year: 2015 (xlvii)

Abstract

Once abundant throughout the Colorado River and its tributaries the razorback sucker Xyrauchen texanus is now critically imperiled and dependent on stocking to perpetuate its existence. Measures taken to stave off extinction began more than 30 years ago, and have succeeded by maintaining mostly isolated adult populations that are not self-sustaining. Short term measures designed to reverse the decline in abundance have become medium term solutions due to lower than expected survival of stocked fish and continued low to absent natural recruitment. The common impediment to producing self-sustaining populations is the presence and continued invasion of nonnative fish species. However, each population of razorback sucker is exposed to a different suite of nonnative fish species, and those differences are evident in estimates of survival at different life stages. As longer term solutions to razorback sucker are pursued, estimates of population specific demographics should inform stocking programs to provide the largest return on limited invested resources.