Blue Water Fish - Secret #4 – Gill Condition, Bloodlines, Color, and Fishy Fish

The color of a fish’s gills is a major indicator of how fresh the fish is. The gills will start out bright red, then turn to red, dark red, light brown, brown, dark brown, then green as the fish ages.

The bloodline is also an excellent method to tell the quality and freshness of a fish fillet or steak. The blood line changes color the exact same way as the gills, turning from bright red to dark brown, then green.

Tuna has to be a deep red color. Flounder and other whitefish have to be a pure, brilliant white color.

Four-fifths of the salmon flesh consumed in the U.S. isn’t naturally pink—it’s gray. Wild salmon eat a lot of krill, crabs, and shrimp. These shellfish are high in a carotenoid called astaxanthin, which gives the salmon their pale pink-red color. Fish farmers feed the salmon with pellet foods containing an artificial version of astaxanthin. This highly processed feed may also contain shrimp-industry waste products or artificial coloring to make their salmon resemble that of their wild counterparts. One company, DSM, even developed a “SalmoFan” – a numbered, color reference tool comparable to what you find when buying house paint that helps fish farmers measure how red their salmon’s flesh color is.

While looks can be deceiving, the smell of a fish cannot be faked. Seafood lovers everywhere know that fresh fish does not smell. Fish that does smell means it is poor quality, has been frozen and refrozen multiple times, and is a few days away from rotting completely.