Toxicity of quinaldine to selected fishes

Quinaldine, an anesthetic for fish, is toxic to various sizes of rainbow trout, brown trout, brook trout, lake trout, northern pike, channel catfish, bluegills, largemouth bass, and walleyes. Toxic concentrations range from 2.0 to 25 ppm in standard tests at 12 degrees Centigrade in 96 hours. The anesthetic is more toxic to fish in hard water than in soft water, a condition probably associated with pH. Safety indexes show that shorter exposures to quinaldine are safer to fish, although the concentrations may be greater than required in longer exposures. Recovery from anesthesia is good among survivors in fish exposed to partial-kill concentrations of quinaldine for 96 hours.