Lake Whitefish Diet and Growth after the Introduction ofMysis relictato Flathead Lake, Montana

Abstract

Diet and growth were compared for lake whitefish Coregonus clupeaformis caught before and after the recent introduction of Mysis relicta to Flathead Lake, Montana. Most foods and seasonal feeding patterns were similar, except that lake whitefish now also eat mysids. Mysids were eaten by fish larger than 100 mm total length, and especially by fish larger than 400 mm collected in the fall. Mean length at first annulus was less in most years following the mysid introduction than before (Student's /, P < 0.05). Mean lengths at other annuli were similar between the two periods. Larger lake whitefish may be less sensitive to reduced zooplankton abundance caused by mysid predation because they feed on benthic fauna. They may also benefit from the recent availability of mysids for their diet.

Lake trout demographics in relation to burbot and coregonine populations in the Algonquin Highlands, Ontario

“…In support Carl (2000) found that 6% of cisco contained an average of 11 fish larvae in Lake Opeongo gillnetting while Hoff et al (1997) also found fish in Lake Superior cisco diet. Three studies found small fish in lake whitefish diet (Tohtz 1993;Doyon et al 1998;Pothoven 2005). Another potential factor is cannibalism.…”

“…In addition Hoff et al (1997) and Carl (2000) found fish larvae in cisco stomachs. Lake whitefish, C. clupeaformis, diet studies have also found small fish consumed (Tohtz 1993;Doyon et al 1998;Pothoven 2005). This suggests coregonines may have an impact on lake trout demographics through predation as well as competition.…”

Forecasting the ecological impacts of the Hemimysis anomala invasion in North America: Lessons from other freshwater mysid introductions

“…Data are for Mysis diluviana in North American lakes and Mysis relicta in Scandinavian lakes. on benthic invertebrates (Tohtz, 1993). Benthivorous fishes such as percids, centrarchids and small-sized burbot (Lota lota) seem to benefit from the availability of mysid prey (Bowles et al, 1991;Langeland et al, 1991b).…”

“…In some lakes, introductions of mysids have stimulated the increased growth of salmonids Stafford et al, 2002); in most other lakes, they are associated with declines in the growth, abundance and productivity of planktivorous fishes (Bowles et al, 1991;Langeland et al, 1991a,b;Lasenby et al, 1986;Rieman et al, 1979;Spencer et al, 1991;Tohtz, 1993). In lakes where kokanee salmon have collapsed following mysid introductions, lake trout may switch from piscivory to planktivory and suffer reduced growth, although their population may increase (Bowles et al, 1991;Morgan et al, 1978;Stafford et al, 2002).…”

Spatio-temporal trends in the food habits of age-0 lake whitefish

“…Studies of sub-adult and adult lake whitefish food habits have shown that these life stages are benthivorous generalists. For example, amphipods, especially Diporeia spp., and chironomid larvae are the most commonly encountered prey items, particularly in Great Lakes populations, but most benthic taxa are represented in the diet (Bajkov, 1930;Hart, 1930Hart, , 1931Van Oosten and Deason, 1939;Watson, 1963;Kliewer, 1970;Colby and Washburn, 1972;Bell et al, 1977;Dion and Whoriskey, 1992;Tohtz, 1993;Tolonen et al, 1999;Pothoven et al, 2001;Hondorp et al, 2005;Pothoven, 2005;Madenjian et al, 2006;Pothoven and Nalepa, 2006). However, there are a number of physiological and morphological requirements that must be met to enable the shift to feeding on benthic food sources in deeper environments and these are poorly quantified for juvenile lake whitefish.…”