ON THE RED COLOR OF THE FLESH IN 

 THE SALMONS AND TROUTS 



By Professor Edward E. Prince, LL.D., M.A., D.Sc, 



F.R.S.C, Commissioner of Fisheries for 



Canada, Ottawa. 



Various theories have been expounded to explain the 

 characteristic red color of the flesh of salmon and trout, 

 and as all these seem to involve difficulties, in my opin- 

 ion fatal difficulties, it seems to me that some explana- 

 tion must be sought to which less objection can be raised. 



Is Color Due to Food? 



The common view is that the food upon which the fish 

 feed gives the characteristic tint to the flesh. The late 

 Dr. Giinther, of the British Museum, emphatically held 

 this view and pointed out that the coloring matter in 

 shrimps and other crustaceans (which turns red when 

 subjected to the digestive fluids, or boiled, or treated 

 with alcohol) is chemically the same as that present in 

 the flesh of salmon and trout. Many authorities could 

 be quoted in favor of this theory, even Dr. Francis Day, 

 in his well-known work on the "British Salmonidse," re- 

 fers to it several times ; but rather cautiously adds, that 

 it may not be the correct explanation. It is the popular 

 and most widespread view; yet it is almost certainly 

 erroneous. The cases are rare in which the color of the 

 food of any animal directly appears in the muscular tis- 

 sues. Moose meat is not green though green lily-pads 

 and leafy birch-twigs form so large a part of its food, 

 nor is cariboo meat colored by the pale green moss, which 

 largely furnishes it with nutriment. The ruffed grouse 

 has very white breast-muscles, while in the spruce part- 

 ridge the color is dark, though both birds live under very 

 similar conditions and are found in the same localities. 



