Yes, it is best to gut fresh fish before freezing. Wash and scale the fish, then gut it and wash the cavity thoroughly under running water. Pat the fish dry and wrap it in foil then place in a sealed strong plastic bag and freeze. Whole freshwater and oily fish can be stored for two months while white ocean fish can be stored for two to three months.
Whole fish are best when thawed slowly to retain their moisture and texture. Fish steaks and fillets are best thawed too, but they may be cooked from frozen if you increase the cooking time by a third.