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FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Figure 54. — Salmon (Salmo salar). Drawing by H. L. Todd. 



been recorded), whereas the humpback has 14 

 anal rays or more. The tail is only very slightly 

 emarginate in adults, and is almost square in 

 large fish, but is more forked in fish that have been 

 at sea for not more than one year ("smolts" and 

 "grilse"). 



Color. — The salmon is silvery all over while in 

 the sea, with brownish back and with numerous 

 small black crosses and spots on head, body (chiefly 

 above the lateral line), and fins. The young fish 

 (or "parr") are conspicuously marked with 10 or 

 11 dark crossbars while in fresh water, alternating 

 with bright red spots, much like young trout. 

 Fish that have been at sea for only one year 

 (grilse) are marked with a larger number of black 

 spots than the older fish. 



Size. — The largest salmon we find mentioned 

 was an English fish of S3 pounds. None even 

 approaching this size is recorded from our side of 

 the Atlantic, where a 50-pounder is unusual, 

 though fish of 40 pounds are not uncommon in 

 some of the larger rivers emptying into the Gulf 

 of St. Lawrence. Very few fish reach 40 pounds 

 in the Penobscot or St. John Rivers, and 30- 

 pounders are unusual there, the usual run being 

 10 to 12 pounds. Taking one river with another, 

 large and small, 10 pounds may be set as a fair 

 average of the mature Gulf of Maine fish. A 2- 

 foot fish will weigh about 6 pounds, one of 3 feet, 

 16 to 20 pounds, with allowance for individual and 

 seasonal variation. 



Remarks. — The teeth and the scales afford the 

 most certain distinction between small salmon and 

 the New England sea trout (p. 120). In the salmon 

 the roof of the mouth is armed both with a cluster 

 in front and with a row of stout conical teeth 

 running back along the mid-line, easily felt with 

 the finger, whereas the sea trout has the forward 



group only. The scales of the salmon are so large 

 that they are seen easily, whereas those of the 

 trout are so minute that they are hardly visible. 

 Old salmon sometimes lose the teeth on the roof 

 of the mouth, but large size and large scales 

 identify them at a glance. 



It should also be easy to tell an Atlantic salmon 

 from a humpback (should any of the latter still 

 exist in our Gulf) for the black spots on the upper 

 part of the body of the humpback and on its tail 

 fin are more close set and much larger and con- 

 spicuous than the dark markings on a salmon. A 

 more precise difference is that an Atlantic salmon 

 never has more than 10 rays in its anal fin, whereas 

 the humpback always has at least as many as 12, 

 while most of them have 13 to 17. 



The danger will be greater of confusing smallish 

 Atlantic salmon with silver salmon, if the attempts 

 now in progress to establish the latter in our Gulf 

 should succeed, for the two fish look much alike. 

 A reliable criterion is, again, the number of rays 

 in the anal fin, for the silver salmon always has 

 as many as 13 of these, an Atlantic salmon never 

 more than 10. 



Life history. 61 — It is no wonder that the life of 

 the salmon has been the subject of much scientific 

 study and that a whole literature has grown up 

 about it. As everybody knows, the salmon lives 

 the greater part of its life in the sea and makes 

 most of its growth there but spawms in fresh water. 



The salmon are silvery and very fat when they 

 enter fresh-water on the spawning journey, but 



•i Huntsman (Bull. Biol. Board Canada, 21, 1831) has published an exten- 

 sive study of the life history of the salmon of the Maiitime Provinces of 

 Canada, from which we have drawn freely in the following account. See 

 also Huntsman and others (Migration and Conserv. of Salmon, Pub. No. 8, 

 Amer. Assoc. Adv. Sci., 1939) for discussions of the movements of the salmon 

 in Canadian and Newfoundland waters; also Lindsay and Thompson (Rept. 

 Newfoundland Fish. Res. Comm., vol. 1, No. 2, 1932) for an account of the 

 biology of the salmon in the rivers and around the coasts of Newfoundland . 



