Comparison of Survival, Gonad Development, and Growth between Rainbow Trout with and without Surgically Implanted Dummy Radio Transmitters

Abstract The use of radio telemetry to determine fish movement patterns associated with spawning has proliferated in recent years. However, little is known about the effect of surgically implanted radio transmitters on spawning behavior or gonad development of fish collected near the time of spawning. We compared survival, gonad development, and growth between wild rainbow trout Oncorhynchus mykiss with and without dummy radio transmitters that were surgically implanted prior to the fish's spawning period. Wild rainbow trout (mean fork length, 351 mm) were collected from the Yakima River, Washington, on February 5, 1993, with a drift boat electrofisher. Ten fish that met selection criteria had dummy radio transmitters surgically implanted into the intraperitoneal cavity, and ten other fish were retained as controls. All 20 fish were released into a nearby pond and fed daily. After 47 d all fish were measured and weighed, and gonad development and general health were assessed. All fish survived, and there ...