yes fish can freeze up and live, you can't put it in the freezer tho, back in school a teacher put gold fish in a tank and then into a freezer, and when thawed they were dead, the tank that was out side froze solid, and were alive come spring, it has to happen naturally, my brothers koi most of them are like 10 years old now, and they all survive winter year after year.

i cant tell you how many trout and carp i've seen frozen in body's of water.