Communications: Use of Cellulose Acetate Electrophoresis to Rapidly Screen Sauger Broodstock for Sauger–Walleye Hybrids

Abstract To maintain the genetic integrity of their product, hatchery managers and culturists often need to rapidly screen fish that are intended as broodstock for hybridization with closely related species. During March 1995 and 1996, we evaluated the use of cellulose acetate electrophoresis to screen wild saugers Stizostedion canadense from the Peoria Pool of the Illinois River for hybridization with walleyes S. vitreum. Seven of 372 fish (1.9%) in 1995 and 30 of 733 fish (4.1%) in 1996 that had been identified as saugers, based on external morphology and skin pigmentation, were subsequently identified by electrophoresis as sauger–walleye hybrids and were excluded from the breeding program. In addition, polymorphisms at the phosphoglucomutase locus PGM-1* were identified among Illinois River saugers. Cellulose acetate electrophoresis allowed rapid (<30 min) discrimination of saugers from hybrids and promises to be a highly efficient system for screening potential broodstock in a hatchery environment.