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Why Are Salmon Red? Proximate And Ultimate Causes Of Flesh Pigmentation In Chinook Salmon, Sarah Jean Lehnert

Electronic Theses and Dissertations

Carotenoids are responsible for the characteristic red eggs, skin and flesh of salmonids. Although carotenoids are thought to provide salmon with many benefits, carotenoid pigmentation has not evolved in all, or even the majority of fishes, thus highlighting our lack of understanding of the evolutionary costs and benefits associated with the pigment. In nature, Chinook salmon (Oncorhynchus tshawytscha) exhibit extreme variation in carotenoid utilization due to genetic polymorphisms that affect carotenoid deposition into the flesh, skin and eggs, consequently resulting in two colour morphs (red and white). Chinook salmon are thus an ideal model species to study carotenoid pigmentation evolution. …