Skip to main content
U.S. flag

An official website of the United States government

Sperm quality assessments for endangered razorback suckers Xyrauchen texanus

December 6, 2011

Flow cytometry (FCM) and computer-assisted sperm motion analysis (CASA) methods were developed and validated for use with endangered razorback suckers Xyrauchen texanus collected (n=64) during the 2006 spawning season. Sperm motility could be activated within osmolality ranges noted during milt collections (here 167–343 mOsm/kg). We hypothesized that sperm quality of milt collected into isoosmotic (302 mOsm/kg) or hyperosmotic (500 mOsm/kg) Hanks' balanced salt solution would not differ. Pre-freeze viabilities were similar between osmolalities (79%±6 (S.E.M.) and 76%±7); however, post-thaw values were greater in hyperosmotic buffer (27%±3 and 12%±2; P=0.0065), as was mitochondrial membrane potential (33%±4 and 13%±2; P=0.0048). Visual estimates of pre-freeze motility correlated with total (r=0.7589; range 23–82%) and progressive motility (r=0.7449) by CASA and were associated with greater viability (r=0.5985; P<0.0001). Count (FCM) was negatively correlated with post-thaw viability (r=-0.83; P=0.0116) and mitochondrial function (r=-0.91; P=0.0016). By FCM-based assessments of DNA integrity, whereby increased fluorochrome binding indicated more fragmentation, higher levels were negatively correlated with count (r=-0.77; P<0.0001) and pre-freeze viabilities (r=-0.66; P=0.0004). Fragmentation was higher in isotonic buffer (P=0.0234). To increase reproductive capacity of natural populations, the strategy and protocols developed can serve as a template for use with other imperiled fish species, biomonitoring, and genome banking.

Publication Year 2011
Title Sperm quality assessments for endangered razorback suckers Xyrauchen texanus
DOI 10.1530/REP-10-0153
Authors Jill A. Jenkins, Bruce E. Eilts, Amy M. Guitreau, Chester R. Figiel, Rassa O. Draugelis-Dale, Terrence R. Tiersch
Publication Type Article
Publication Subtype Journal Article
Series Title Reproduction
Index ID 70003614
Record Source USGS Publications Warehouse
USGS Organization National Wetlands Research Center