The science behind the fish flesh rainbow


Fish flesh can run the gamut from ruby red (yellowfin tuna) to electric blue (lingcod), and NPR's The Salt blog has a handy explainer on the reasons behind those vibrant colors.
Yellowfin tuna, for example, is the "Michael Phelps of the fish world," and needs a lot of oxygen to go to its muscles. A protein called myoglobin stores that vital oxygen and also serves as a pigment, making the flesh pinkish red. "It's true of land animals, too: If they're walking around a lot, they'll have more myoglobin and their meat will be darker," says zoologist Bruce Collette.
Chinook salmon eat krill, which are filled with pigments called carotenoids; those carotenoids then turn the meat orange. Lingcod are bottom-dwelling fish whose blood serum turns blue due to a bile pigment called biliverdin. Then there's boring old halibut, which is off-white because it is a rather slow fish (it's no tuna) and often just chills on the sea floor. Read more about what makes fish flesh so colorful (or not, sorry halibut) at NPR.
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Catherine Garcia has worked as a senior writer at The Week since 2014. Her writing and reporting have appeared in Entertainment Weekly, The New York Times, Wirecutter, NBC News and "The Book of Jezebel," among others. She's a graduate of the University of Redlands and the Columbia University Graduate School of Journalism.
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