Assessment of Growth and Relative Survival of Diploid and Triploid Saugeye in Kansas Impoundments

1. Saugeye Sander vitreus x Sander canadensis are commonly stocked by fisheries managers in the Midwest to establish percid populations in waters with marginal walleye Sander vitreus habitat.  Although saugeye are a true hybrid, they are capable of producing viable progeny and backcrossing with parental species.  As such, there are concerns regarding unintended reproduction of stocked fish and genetic contamination of percid populations.  To alleviate these concerns, Kansas periodically stocks triploid saugeye that are incapable of producing viable offspring.  The objective of this study was to evaluate stockings of diploid and triploid saugeye by stocking equal numbers of saugeye fry in five Kansas reservoirs and examining their subsequent survival and growth.  In the first two years of the study (i.e., 2014 and 2015), 500 saugeye have been sampled from five reservoirs using night electrofishing.  In 2014, 44 of 200 (23%) of sampled age-0 saugeye were triploid.  Similarly, in 2015, 50 out of 300 (17%) age-0 and age-1 saugeye were triploid.  Trends in relative survival by reservoir have been consistent; however, differences in growth of diploid and triploid saugeye have been variable.  In general, growth of diploid saugeye has been greater than that of triploids.