Four months. But it is best to eat within 2 months, a study showed that the fish will be placed at minus 18 degrees to save three months, the loss of nutrients contained in the fish is very obvious, especially vitamin A and vitamin E, roughly 20% -30% loss. Moreover, freezing does not stop the deterioration process of fish, and fish proteins will still decompose to produce soluble toxic proteins and other harmful substances. If the thawing of the fish found in the head with brown spots, yellow abdomen, you can not eat.