How to Identify Fresh Fish?

The best ways to identify fresh fish are to see, touch, and smell.

1. Look for bright shiny color skin with firmly attached scales. The fish should be quite slippery and moist. As a fish sits, its skin becomes more pale and dull looking, sometimes almost translucent; and its scales start dropping.
   
2. The eyes of freshly caught fish look black and beady(clear). Milky or sunken eyes are signs that a fish has been dead too long.
   
3. When you lift up the gill flap, you should see bright firm coral-red gills (moist). Older gills become marked with red-black clots, or grey in color. The gills should not be missing, that's a sign that the handlers took it out to hide the amount of time that the fish has been out of the water.
   
4. When you gently poke the flesh, it should feel firm and resilient, almost rubbery. As the flesh ages, it rebounds less to finger pressure and the indentation remains.
   
5. Fresh fish should smell like a delicate scent of the ocean and not a fishy smell.
   

Usually only the freshwater fish and shellfish get sold from live tanks, in part because saltwater tanks cost a lot to maintain. However, live fish from tanks are not necessarily better than frozen. Dirty tanks can impart bad flavors. Crowded conditions can stress the fish, also affecting flavor.

Fish that have been frozen immediately after catching can maintain fresh flavors for weeks. Fish on ice (not frozen) will stay fresh for several days and generally have the best texture. Once thawed, fish should not be re-frozen. If you buy live fish or fish on ice, you should eat it the same day.