WHY, SALMON ARE PINK

Evening Post, Volume CIV, Issue 67, 16 September 1922, Page 12

WHY, SALMON ARE PINK

v • . . ■A PUZZLE FOR NATURALISTS,.

; Men of science were long puzzled to know why the' various salmon and trout have red or pink flesh. Now they believe, that the colour comes from the.food they eat (observes the " Youth's Companion "). All of the salmon family are particularly fond of shellfi»si; 'and trout eagerly feed on fresh-water shrimp. It js well known that when lobsters, prawns, and shrimp are cooked the flesh turns pink f'similarly the process of digestion tur&s: ; slfeHfish pink. When a shrimp in found in the stomach of a salmon or a trout the^.gastric juices qf the fjah have turned jt almost as red. or pink as if it had been boiled. Therefore, even if we had no definite proof, we might believe that the colour of-the fish of salmon and trout results from the considerable quantities of various small shellfish that the fishes eat. . But there is definite proof. Several years ago Professor I*eger, of the Piscicultural Laboratory at Grenoble, France, made experiments with trout to determine what gave their flesh its colour. He separated the eggs from one trout into two lots, and hatched them in different troughs. He fed 'one tot of young fish exclusively on, freshwater shrimps; to the other lot he gave mo shrimps whatever. At the end of the' second year the trout that had fed on shrimps had salmon-coloured flesh, 1 but the flesh of the other trout was perfectly tf/hite. But someone may ask, why is the flegh of shellfish red or pink? That is a hard question-to answer^ Perhaps ■flic colour comes from the food the shellfish eat. ' ; '