sad topic, but I want to learn about this in case I have to do it one day.
page 20 of the document contains information on how to euthanize fish. In particular, freezing fish causes crystalization on tissues and skin, and causes suffering. I don't think I can do "physical" methods like blow to the head...
It sounds like Benezocaine hydrochloride, 2-phenoxyethanol, Tricaine methan sulfonate are safe, very fast, effective and easy to use solutions.
where can I get this kind of chemical? When they say these work fast, but are expensive, how expensive are they talking about?