2001 Safest level of tricaine methanesulfonate
(MS-222) to induce anesthesia in juveniles of matrinxa, Brycon cephalus.
After collection of larvae, they were anesthetized with tricaine methanesulfonate
(MS 222), washed with distilled water to remove the excess of salts and frozen at -70[degrees]C until the analysis.
Euthanasia was performed in accordance with the American Veterinary Medical Association Guidelines for the Euthanasia of Animals (AVMA, 2013); primary euthanasia was exposure to buffered, pharmaceutical-grade tricaine methanesulfonate
(MS-222), followed by decapitation as a secondary method.
At 48 hpf, embryos were screened for malformations, and the morphologically normal animals were euthanized by overdose of buffered tricaine methanesulfonate
(MS-222, 200-300 mg/L) by prolonged immersion and monitored under a dissecting microscope until their hearts stopped beating (approximately 15 min).
The most commonly used anesthetics for fish are tricaine methanesulfonate
(MS-222), benzocaine, metomidate, 2-phenoxyethanol and quinaldine.
Fish were transferred to a small cooler with 65 mg/L tricaine methanesulfonate
and anesthetized to a point that induced loss of equilibrium but still allowed opercular movement.
Before experiments, animals (n = 57) were deeply anesthetized by immersion in lamprey Ringer solution containing 0.1% tricaine methanesulfonate
(ScienceLab, Houston, TX, USA).
After being anesthetized with tricaine methanesulfonate
(50mg [L.sup.-1]) (MS222 SIGMA), the fish were euthanized and dissected in accordance with the procedures approved by the UFRA ethics committee for animal experimentation.
As a positive control, from stock solution of tricaine methanesulfonate
(1mg/ml) serial dilutions were made in the range of 0.05 ug/ml - 100ug/ml in DMSO.
After collection, fish were euthanized by overdose of tricaine methanesulfonate
(MS222; Western Chemical, Ferndale, Washington), stored in a cooler with ice, and transported to the MFWP Fish Health Laboratory in Great Falls, Montana.
or MS222 can be administered in many different ways in order to cause death.