Tricaine mesylate
（重定向自Tricaine）
Tricaine mesylate (Tricaine methanesulfonate, TMS, MS-222), is white powder used for anesthesia, sedation, or euthanasia of fish. TMS is the only anesthetic licensed in the United States for fin fish that are intended for human consumption. The drug can have selective toxicity for poikilotherms due to their lower rate of metabolism in the liver.