euthanize fish?

[BCWolfen]

Fish like all cold blooded animals or amphibians metabolism slows down as they get colder. IE I stop feeding my goldfish in the pond as winter approaches because they just don't eat. They get lethargic, slow down and slowly idle round near the bottom. As winter progresses they slow down even more to a 'near hibernation' state until spring. A fish put into the freezer in warm water will do the same. His metabolism slowing down until, in the case of a freezer, he quietly slides into sleep, coma, death. Quiet and calm no stress.