Effects of nonlethal sea lamprey attack on the blood chemistry of lake trout

A laboratory study examined changes in the blood chemistry of field-caught and hatchery-reared lake trout Salvelinus namaycush subjected to a nonletha l attack by sea lampreys Petromyzon marinus. We measured glucose, total pro tein, amylase, alkaline phosphatase (ALKP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase, calcium, magnesium, tri glycerides, sodium, and potassium with a Kodak Ektachem DT60 Analyzer, Ekta chem DTSC Module, and the DTE Module. Mean levels of total protein, AST, AL KP, hematocrit, calcium, magnesium, and sodium decreased significantly (P l ess than or equal to 0.05), and mean levels of ALT and potassium increased significantly (P less than or equal to 0.05) after sea lamprey feeding. Lak e trout condition (K) and hematocrit levels also decreased significantly (P less than or equal to 0.05) after the sea lamprey attack. Frequency distri butions of eight lake trout blood chemistry variables and the hematocrit we re significantly different before and after a sea lamprey attack. A second study that used hatchery lake trout broodstock measured changes in hematocr it before and after a sea lamprey attack.