FISHES OF THE GULF OF MAINE 



133 



lished. 1 But natural reproduction seems not to 

 have been successful enough for the humpback to 

 maintain itself in the few Maine rivers open to it, 

 much less to increase in numbers, for very few have 

 been reported since about 1926 or 1927, and none 

 that we have heard of for some years past. 



Silver salmon Oncorhynchus kisutch 

 (Walbaum) 1792 



COHO SALMON 

 Jordan and Evermann, 1896-1900, p. 480. 



Description. — The silver salmon resembles a 

 rather stout Atlantic salmon closely in its general 

 shape, also in the relative size and position of its 

 fins, and in their shapes. But a safe morphologi- 

 cal criterion for distinguishing the one from the 

 other is that the silver always has at least 12 

 rays in its anal fin, and some of them have as 

 many as 17, whereas most of the Atlantic salmons 

 have only 8 or 9 anal rays, and never more than 

 10. The color is a help also, in this connection, 

 for while a silver is silvery down its sides, like an 

 Atlantic salmon, it is more closely sprinkled with 

 small black spots along its back and on the upper 

 part of its tail fin than is an Atlantic salmon. 

 These spots, too, are always roundish or oval in 

 a silver, never in the form of crosses. On the 

 other hand, the black spots are much smaller and 

 much less conspicuous on a silver salmon than on 

 a humpback, and the lower half of the tail fin, 

 which is as conspicuously spotted as the upper 

 half on a humpback, usually has no spots on a 

 silver salmon. 



Size. — Up to 3 feet in length. 



General range, habits, and occurrence in the Gulf 

 of Maine. — The native range of the silver salmon 

 is from northern California to northwestern Alaska, 

 where it is an important food fish, and where 

 anglers take many of them, both by trolling and by 

 fly fishing. Like other Pacific salmons, it runs 



i Rept. of U. 8. Comm. Fish. (1928), Pt. 1, 1929, p. 379. 



up into fresh streams to spawn, dying thereafter- 

 Most of the young remain about one year in 

 fresh water, but a few do not move out to sea 

 until they are in their third year. Most of them 

 return to fresh water at the end of the third 

 summer at sea, a few, however, by the end of the 

 second summer in salt water, a few others not 

 until the fourth summer. 



Our only reason for mentioning the silver salmon 

 is that a plant of its fry and fingerlings that was 

 made in the Duck Trap stream, tributary to the 

 western side of Penobscot Bay, near Lincolnville, 

 Maine, resulted in the return of 150 mature fish 

 to Duck Trap stream in 1944, and perhaps of 

 more of them. But nothing more was heard of 

 them thereafter, and no returns have been re- 

 ported up to this writing (Nov. 1, 1951) from 

 other plants that were made in Maine waters 2 

 in 1948. 



THE SMELTS. FAMILY OSMERIDAE 



The smelts are small salmons in all essential 

 respects, except that their stomach has few pyloric 

 caecae, or none, whereas there are large numbers 

 of such caecae in their larger relatives of the salmon 

 family. However, it is not necessary to look so 

 deeply to learn whether a fish be smelt or v e ry 

 young salmon, for the former all have pointed 

 noses and are very slender, whereas the young of 

 our four salt-water salmons — humpback, silver 

 Atlantic, and sea trout — are much stouter, with 

 blunt noses. In most cases, too, the shape of 

 the tail would suffice of itself to separate smelt 

 from salmon smolt, for it is never as deeply forked 

 in the latter as in the smelts. 



Two smelt fishes occur in the Gulf of Maine: 

 the smelt (very common), and the capelin (a 

 sporadic visitor from the north). The argentine 

 (p. 139) is so closely related to the smelts that it is 

 included in the following key. 



» In Tunk stream, Duck Trap stream, Chandler River, and Bald Hill 

 Cove Brook. 



KEY TO GULF OF MAINE SMELTS AND ARGENTINES 



The dorsal fin originates over the tips of the pectorals; the mouth is very small Argentine p. 139 



The dorsal fin situated far behind the pectorals; the mouth is large 2 



Upper jaw almost as long as lower; teeth large; there is a group of strong fangs on the tongue; the pectoral fins have 12 



rays or fewer.. Smelt, p. 135 



Lower jaw much longer than upper; teeth so small as hardly to be visible; no fangs on tongue; the pectoral fins have 



15 to 20 rays.. Capelin, p. 134 



