Gilderhus, P. A., 1989, Efficacy of benzocaine as an anesthetic for salmonid fishes:
North American Journal of Fisheries Management, v. 9, no. 2, p. 150-153.

Abstract: 

Benzocaine was tested in the laboratory to determine the effective concentrations
for anesthetizing juvenile chinook salmon Oncorhynchus tshawytscha an rainbow
trout O. mykiss (formerly Salmo gairdneri ). Tests were conducted at three water
temperatures, in waters ranging from very soft to very hard, and with groups of
rainbow trout from 5 to 47 cm long and chinook salmon 20 cm long. Effective
concentrations were defined as those that rendered the fish fully handleable in 3
min or less, allowed recovery of most fish within 10 min, and caused no mortality
after 15-min exposures. Concentrations of 25-45 mg/L anesthetized both species
over the entire range of conditions tested. Although efficacy was essentially
unrelated to species or water quality, it was related to water temperature and size of
fish; the concentrations of benzocaine required were highest at the lowest water
temperature and for the largest fish.

Keywords: 

bioassays, fish-handling, Oncorhynchus-tshawytscha, Salmo-gairdneri,
Oncorhynchus-mykiss, anaesthetics; benzocaine-dose, response