Relationship Between Lake Erie Walleye Gamete Viability And Concentrations Of Vitamins B1 In Eggs And Sperm

Thiamine (vitamin B1) has major impacts on survival of embryonic and early life stages of fish. Low levels of thiamine, a water-soluble vitamin, in eggs have been responsible for early mortality syndrome (EMS) in salmonids from the lower Great Lakes (Marcquenski, 1996), Cayuga syndrome in Atlantic salmon Salmo salar from the Finger Lakes region (Fisher et al., 1995), and M74 (another EMS-like cause of mortality) in Baltic Sea salmon (Bengtsson et al., 1994). Fisher et al. (1996) concluded that the increase in salmonid alevins mortality from Cayuga Lake was directly linked to broodfish diets consisting only of alewife Alosa pseudoharengus and rainbow smelt Osmerus mordax. These two nonindigenous species, as dominant forage fishes in Cayuga Lake, contain thiaminase, an enzyme that destroys thiamine (Fisher et al., 1995, 1996). Similar conclusions were drawn by Fitzsimons and Brown (1998) with respect to lake trout Salvelinus namaycush in the Great Lakes. Alewife and rainbow smelt also have been reported to be the main prey of walleye in northern Lake Michigan (Madenjian et al., 2  2) and the western basin of Lake Erie (Morrison et al., 2   ), leading to the potential that walleye Stizostedion vitreum could suffer EMS.