Alterations in the Blood Level of Lactic Acid in Certain Salmonoid Fishes Following Muscular Activity.: II. Lake Trout,Salvelinus namaycush

Abstract

During the summer of 1954, 1½-year-old, hatchery-raised lake trout, Salvelinus namaycush, were subjected to 15 minutes of severe muscular exercise at the trout hatchery at Summerland, B.C. Following exercise, fish were allowed to recover for various intervals up to 24 hours. Blood samples were taken and analyzed. The hemoglobin levels did not change significantly, the blood glucose increased significantly during the second hour of recovery. Except for dips at the 6th and 12th hours, this high level of glucose persisted to the end of 24 hours. The blood level of lactic acid increased sevenfold immediately following exercise and continued to increase during the first two hours of recovery. The lactic acid level declined rapidly between the 2nd and 6th hour. The initial low unexercised level was reached by the end of 24 hours. The hemoglobin and lactic acid changes were very similar to those noted for Kamloops trout, Salmo gairdneri.