Fishes of the IF es tern North Atlantic 463 



The smolt (p. 467) is silvery due to the deposition of light-reflecting spicules of 

 guanin in the epidermis, covering the bars and spots of the parr so that it resembles 

 the adult Salmon at sea. 



Changes in Spawning Fish. As spawning approaches, the head (snout and lower 

 jaw particularly) elongates, and the lengthening of the lower jaw is greater than that 

 of the skull itself; and in the male the tip of the lower jaw turns upward to form 

 a prominent hook that fits (when the mouth is closed) into a hollow of the upper jaw. 

 These changes are more pronounced in the male than in the female, and in both sexes 

 they are relatively much greater in large specimens than in small ones (i2y). After 

 spawning is completed, in those that live, these changes gradually disappear and the 

 features of the head resume their normal shape and proportions. 



Figure 121. Salmo salar, smolt stage, 140 mm TL, from Margaree Harbor, Cape Breton, Nova Scotia, ROMZ 

 9462. Drawn by Jessie H. Sawyer. 



The teeth also undergo very marked changes with each breeding period (126). 

 The "feeding teeth" are replaced by special "breeding teeth" when the fish moves in- 

 shore towards the river. These are relatively shorter and broader at their bases than the 

 feeding teeth, and on some bones they are strongly curved; when fully grown in large 

 males, the breeding teeth are securely fastened to the bones. When spawning is com- 

 pleted they are apparently replaced again by feeding teeth. In specimens of equal size, 

 the number of breeding teeth on the maxillaries is higher than the number of feeding 

 teeth. In the large breeding males examined, the vomerine teeth on the anterior part 

 of the shaft were in a transverse row. Tchernavin's observations are supported by those 

 of Rushton (118), who found that well-mended kelts (p. 467) had large teeth, with 

 small teeth beginning to grow between them. The large teeth showed signs of decay 

 at their bases and looked as though they would drop out before long. In addition to 

 the striking changes in head and teeth, the skin of the back becomes thick and spongy 

 and the scales are embedded. 



Size. This species grows larger in European waters than in the western Atlantic, 

 where very few reach 50 pounds (p. 478). The largest ones that have been caught 

 in America by angling were a 55-pound fish taken in the Grand Cascapedia River, 

 Quebec, on July 27, 1939; and two 54-pound fish, one taken there on June 20, 1886 

 (.^35- 50), and the other in 1921.* In some of the larger rivers of Newfoundland and in 



6. See photo in Atlantic Salmon Journal, Sept. 1959: 24. 



