Date of this Version
The Prairie Naturalist 47:41–44; 2015
Food habits of age-0 fishes can influence their growth and survival prior to the first winter (Hoxmeier et al. 2006, Shoup and Wahl 2011). Ontogenetic diet shifts in juvenile piscivorous fishes result in a transition in consumption from zooplankton to macroinvertebrates and eventually fish throughout development (Mittelbach and Persson 1998). Certain food items may be more energetically beneficial to fishes than others as consumption of prey fishes may lead to faster growth rates of predators, decreased overwinter starvation, avoidance of competition, and reduced predation risk (Werner and Gilliam 1984). By the time age-0 walleyes (Sander vitreus) have reached lengths of 60–80 mm total length (TL), their diets are predominantly composed of fish (Priegel 1969, Quist et al. 2002, Galarowicz and Wahl 2005). Previous studies have examined age-0 walleye food habits in South Dakota in a limited number of waters at various times and the majority of fall diets were composed of fish (Beck et al. 1998, Blackwell et al. 1999). Fathead minnows (Pime- phales promelas), rainbow smelt (Osmerus mordax), yellow perch (Perca flavescens), darters (Etheostoma spp.), and gizzard shad (Dorosoma cepedianum) have all been documented as regionally important prey fish species for juvenile walleyes (Jackson et al. 1992, Beck et al. 1998, Blackwell et al. 1999, Pelham et al. 2001, Uphoff 2012). Although generalized feeding ecology of walleye during early life stages has been investigated, previous studies have only examined food habits in either a controlled setting or limited number of waters, thereby potentially overlooking spatial differences in feeding ecology. Therefore, this study examined food habits of age-0 walleye collected during fall across a range of eastern South Dakota glacial lakes.