💀 Euthanasia¶

Euthanasia is the practice of ending an animal's life to relieve its suffering. It comes from the greek words eu (good) and thanatos (death).

Euthanasia is performed when a fish exhibits signs of severe illness or distress that compromises its quality of life as well other fishes in the tank. Indicators that euthanasia may be necessary include unusual swimming patterns, loss of balance, discoloration, gasping for air at the surface, lethargy, fin rot, or signs of ich. Researchers are advised to exercise their discretion when deciding to euthanize fish. The following guidelines provide a step-by-step process for euthanizing fish safely and effectively.

1. Fish should be anesthetized using rapid chilling. The primary method the Kao Lab uses for rapid chilling is via using an ice bath. To gather ice for this procedure, use one of the transparent fiber containers and fetch some ice from ISC 5500 (Siegfried/McCusker Lab).
2. Setup the clear plastic glass half filled with water over the ice bath and allow it chill over 5 minutes.
3. Place the fish in the glass and monitor the water temperature with a thermometer to maintain it between 1-4 degrees Celsius. Fish should remain in the ice bath for at least 10 minutes after gill movement has ceased. Ensure that the fish do not come into direct contact with the ice, and limit the density to no more than 40 fish per liter of ice water.
4. Carcasses are to be incinerated with other vivarium waste. After gill movement cease to exist, move the fish into a zip loc bag with proper labelling and deposit the bag at the -20 freezer in the necropsy room labeled for aquatics.
5. After euthanasia, sterilize the euthanasia container before returning it to use.