Habitat Preferences, Survival, Growth, Foods, and Harvests of Walleyes and Walleye × Sanger Hybrids

Abstract

We compared habitat preferences, survival, growth, foods, and harvests of stocked walleyes Stizostedion vitreum and walleye ♀ × sauger S. canadense ♂ hybrids in Pleasant Hill Reservoir, Ohio. Both fishes were stocked at similar rates and sizes (about 40 mm mean total length) in late May or early June 1979–1982. Neither group showed consistently better survival. Growth was similar until age 2. Thereafter, hybrids grew faster than walleyes. Age-0 walleyes occurred mostly over fine substrates in early summer and coarse substrates by fall. Habitat selection by age-0 hybrids was similar to that of walleyes, except hybrids preferred finer substrates in fall. Older hybrids and walleyes moved offshore at temperatures above 22°C. Diets of both fishes were similar, but hybrids ate more littoral fishes, whereas walleyes ate more pelagic fishes. Age-1 and older hybrids and walleyes ate mostly invertebrates in spring. Age-0 gizzard shad Dorosoma cepedianum were the most important prey for all ages of both groups. Hybrids and walleyes were caught by anglers in proportion to their abundances and contributed most to the fishery at ages 1 and 2. Hybrids have the potential to breed with either parent species and may introduce new genetic material into existing walleye or sauger populations. Data from our study and other Ohio waters show that hybrids can support important fisheries, particularly in tailwaters, and may be more successful than walleyes in impoundments with short water-retention times.