Effects of simulated light intensity, habitat complexity and forage type on predator–prey interactions in walleye Sander vitreus

Abstract

Predator-prey interactions can be influenced by the behaviour of individual species as well as environmental factors. We conducted laboratory experiments to test for the influences of two abiotic factors (light intensity and habitat complexity) on predator-prey interactions between walleye Sander vitreus and two prey species, bluegill Lepomis macrochirus and golden shiner Notemigonus crysoleucas. Three light intensities were simulated (day, twilight and night) in the presence or absence of simulated vegetation. Observations of predator behaviour indicated that walleye increased activity and foraging success with decreasing light levels and had most success capturing dispersed, closer prey. While schooling could not be maintained as light levels diminished, prey decreased predation vulnerability by moving into vegetation or higher in the water column. Throughout all treatments, bluegill were more evasive to capture as the number of strikes was similar on both prey but capture rates were higher for golden shiner. Although light intensity and simulated habitat complexity affected predator and prey behaviour, these factors did not interact to influence foraging success of walleye. To fully understand predator and prey behaviours in fishes, an understanding of species-specific responses to abiotic and biotic factors is necessary.

Neutral effects of turbidity across a gradient of vegetation density on the predation of juvenile mandarin fish (Siniperca chuatsi)

“…A couple of studies of other vegetation systems have also provided similar results (Hawkins, Armstrong, & Magurran, ; Horinouchi et al, ). In contrast, most research on other fishes report that dense vegetation reduces the feeding efficiency (Einfalt, Grace, & Wahl, ; Ferrari et al, ; Gregory & Levings, ). With increasing vegetation density, piscivores suffer diminished visual range along with reduced mobility, as vegetation acts as a barrier to predator movement (Einfalt et al, ).…”

“…In contrast, most research on other fishes report that dense vegetation reduces the feeding efficiency (Einfalt, Grace, & Wahl, 2012;Ferrari et al, 2014;Gregory & Levings, 1996). With increasing vegetation density, piscivores suffer diminished visual range along with reduced mobility, as vegetation acts as a barrier to predator movement (Einfalt et al, 2012). In addition, some studies have also shown that aquatic vegetation had no effect on predation (Minello & Zimmerman, 1983).…”

“…The effects of vegetation density on predation of different fish species were not consistent (Einfalt et al, 2012;Gregory & Levings, 1996;Horinouchi et al, 2009). One possible reason for this inconsistency is that predator-prey interactions can be influenced by the foraging tactics of predators and antipredation behavior of prey, as well as environmental factors (Einfalt & Wahl, 1997;Einfalt et al, 2012). Laurel and Brown (2006) suggested that the ambush predator Myoxocephalus scorpius, likely took advantage of the visual impairment of prey in vegetation.…”

Visual performance impaired by elevated sedimentary and algal turbidity in walleye Sander vitreus and emerald shiner Notropis atherinoides

“…In addition, this species has a visual adaptation that increases scotopic (low light) visual capabilities (Wahl, ), providing a potential advantage under turbid conditions; the tapetum lucidum, a reflective layer of tissue behind the retina, that increases the amount of light that passes through the retina (Ali & Anctil, ). Sander vitreus forage primarily in lower light levels ( e.g ., dawn and dusk) with foraging during daylight hours associated with moderate levels of turbidity (2–4.9 m Secchi depth) that result in lower light intensity (Ryder, ; Einfalt et al ., ). However, it is likely that too much light scattering in highly turbid water will pose a threat to the visual abilities of S. vitreus because they rely on vision to detect prey from a distance.…”

The Spatial Ecology and Biological Responses of Wild Fishes Relative to Hydropower Development on the Winnipeg River

“…For example, environmental parameters such as water temperature and flow rate are thought to initiate spawning behaviour in the early spring for Lake Sturgeon (Forsythe et al 2012;Auer et al 2013). Additionally, Walleye are a photophobic species that are generally more active during the crepuscular and nocturnal periods (Swenson and Smith 1973;Kelso 1978;Einfalt et al 2012), while spawning activity and foraging is closely related to photoperiod and water temperature (Ellis and Giles 1965;Ryder 1977). Seasonal movements and habitat selection of Lake Sturgeon and Walleye have been related to ontogeny, water temperature, and flow rates in past research (Auer 1996;Knights et al 2002;Peterson et al 2007).…”