Effect of Capture Stress on Plasma Enzyme Activities in Rainbow Trout (Salmo gairdneri)

Abstract

Four capture methods were used to collect domesticated rainbow trout (S. gairdneri): angling, electroshocking, seining and direct netting (control). Blood was sampled rapidly upon capture, usually within 2 min. No significant differences were noted between the 4 capture groups for plasma protein concentration, lactate dehydrogenase activity or leucine aminonaphthylamidase activity. Creatine phosphokinase activity was elevated among electroshocked fish. Acid phosphatase activity was too low for accurate measurement. Hematocrits were significantly elevated by capture struggles. Results indicate that capture methods do not preclude the use of plasma enzyme levels for investigating the health of wild fish.