Scaphirhynchus Conference: Alabama, Pallid, and Shovelnose Sturgeon

St. Louis, Missouri, 11-13 January 2005

4.  MICROSATELLITE ANALYSIS OF SCAPHIRHYNCHUS SPECIES FROM THE SOUTHEASTERN UNITED STATES

Jeff M. Ray, Department of Biology, Saint Louis University, 3507 Laclede Avenue, St. Louis, MO 63103-2010; Phone 314-977-3904; FAX 314-977-3658; rayjm@slu.edu

Casey B. Dillman, Department of Biology, Saint Louis University, 3507 Laclede Avenue, St. Louis, MO 63103-2010; Phone 314-977-3904; FAX 314-977-3658; dillmanc@slu.edu

Robert M. Wood, Department of Biology, Saint Louis University, 3507 Laclede Avenue, St. Louis, MO 63103-2010; Phone 314-977-3904; FAX 314-977-3658; wood2@slu.edu

Bernard R. Kuhajda*, Department of Biological Sciences, University of Alabama, Box 870345, Tuscaloosa, AL 35487-0345; Phone 205-348-1822; FAX 205-348-6460; bkuhajda@bama.ua.edu

Richard L. Mayden, Department of Biology, Saint Louis University, 3507 Laclede Avenue, St. Louis, MO 63103-2010; Phone 314-977-3494; FAX 314-977-3658; maydenrl@slu.edu

Hybridization between the endangered Pallid Sturgeon, Scaphirhynchus albus, and the sympatric Shovelnose Sturgeon, S. platorynchus, has been reported within the Mississippi and Missouri rivers, with most putative hybrid individuals thought to exist in the lower Mississippi River Basin.  Hybridization hypotheses are based solely on morphological criteria that have been shown to fail in a number of circumstances.  In order to assess whether hybridization is occurring 75 Shovelnose Sturgeon and 60 Pallid Sturgeon were selected and genotyped using 12 microsatellite loci from McQuown et al. (2000).  Seven of these loci are disomic and have been used in a number of previous sturgeon studies.  In addition, we also used five tetrasomic loci which produced some very informative patterns of variation.  This genotyping study is considered a necessary first step as any conclusion of “hybridization” is reliant upon a robust set of baseline genetic data regarding what constitutes both “pure” Pallid and “pure” Shovelnose genotypes to compare with putative hybrid individuals.  Unlike prior studies of this issue, all individuals used in the current analysis are vouchered with either photographs or museum housed carcasses so that any ambiguities in the resulting data can be resolved by inspection of the individual from which the genetic sample was drawn.  The analysis of these data along with their impact for future hybrid studies will be presented in detail and discussed.  It is evident based on our results that proper specimen identification is essential for researchers to collect valid data useful in the management of the endangered pallid sturgeon.