Thermal Requirements of the Early Life History Stages of Walleye, Stizostedion vitreum vitreum, and Sauger, Stizostedion canadense

Abstract

Walleye (Stizostedion vitreum vitreum) and sauger (Stizostedion canadense) eggs were exposed to temperatures ranging from 6 to 21 C to determine temperature effects on fertilization, incubation, and fry survival. Optimum fertilization temperatures were 6–12 C for walleye and 9 C for sauger. Optimum incubation temperatures were 9–15 C for both walleye and sauger. A sharp drop or rise in temperature had no great effect on walleye fry and juvenile survival. Optimum temperature for juvenile walleye and sauger growth was 22 C. When acclimated at 8–26 C, 96-h upper lethal temperatures for walleye juveniles were 27.0–31.6 C, with the lower acclimation temperatures producing the lower upper lethal limits and intermediate acclimation producing intermediate upper lethal limits in order as acclimation temperatures increased. When acclimated at 10–26 C, the 96-h upper lethal temperatures for sauger juveniles was 26.6–30.4 C, in order as with the walleye.