Once the catch has been filleted, it deserves the best possible storage conditions before you eat it. After a good day out, you might have enough for more than one meal and generally most of our shallow water species don't freeze that well. Here's how you can keep your fillets for significantly longer in the fridge and still have pristine fillets that taste like you caught them yesterday.
1. When you catch your fish, iki spike it and put it on ice or better still in an ice slurry immediately.
When you fillet, skin and bone the fish, avoid getting blood on the fillet if at all possible and particularly if you plan to keep it in the fridge for a day or two.
Don't rinse fillets in fresh water. Salt water is OK. you can always wash any odd scales off just before you cook the fillets.
Use one of these containers (a few dollars at any good plastic shop) to store your fillets in the fridge. It has a section that allows any juices released by the fillet to drain and be kept away from the fillets and be removed from time to time. The secret is that this keeps the fillets dry and they will keep for significantly longer in your fridge in one of these containers.