Razorback Sucker ('Xyrauchen texanus') Status, Reproduction, and Recruitment in Senator Wash Reservoir, California:Final rept

摘要

Information regarding razorback sucker (Xyrauchen texanus) at Senator Wash Reservoir, CA, is limited although researchers have documented the presence of adult and larval razorback suckers since reservoir completion. Razorback suckers were initially entrained within Senator Wash Reservoir when dam construction was completed in 1966. An additional 4,857 razorback suckers were stocked into Senator Wash Reservoir from 1987 to 1990. We designed this study to assess the status of adult razorback sucker in Senator Wash Reservoir, identify razorback sucker size and age classes to assess natural recruitment, document the presence or absence of larval fish, determine characteristics of the Senator Wash Reservoir system that facilitate razorback sucker spawning, and determine the overall fish community structure in Senator Wash Reservoir. To meet our objectives, adult and juvenile fish were sampled from October 2002 and July 2004 with the use of night electrofishing, and between July 2003 and July 2004 with the use of overnight trammel net sets. In addition, larval light traps were used to collect larval fish from January to May 2004. All adult razorback suckers were implanted with Passive Integrated Transponder (PIT) tags for a mark-recapture population estimate, and fin clips were collected from razorback suckers for age analysis.