FISHES OF THE GULF OF MAINE 133 



Life history. — It is no wonder that the life of as noble a fish as 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 and makes 

 most of its growth in the sea but spawns in fresh water. In Gulf of Maine rivers 

 this happens in October and early November on sandy or gravelly bottom far 

 upstream, the females smoothing a shallow trough and covering the eggs with 

 gravel. The large (6 to 7 mm.) thick-shelled eggs lie loose on the bottom and 

 develop so slowly in the low temperature of winter that hatching does not take place 

 until late in the following April or early in May. The newly hatched larvae are 15 

 to 18 mm. (0.6 to 0.7 inch) long, and carry a tremendous large yolk sac for about 

 six [weeks, hiding among the pebbles of the spawning bed and taking no food. 

 When the yolk sac is absorbed the little fish begin to swim and feed. These little 

 salmon, known as "parr," soon assume a brilliant coat with 10 or 11 dark trans- 

 verse bars alternating with bright red spots, much like a young trout. 



Parr live in fresh water for longer or shorter periods, according to locality or to 

 other factors not well understood. . In the rivers tributary to the Gulf of Maine 

 probably most of them remain two winters and two summers, running down to sea 

 the third summer, but some may seek salt water toward the end of the second 

 summer (when lj^ years old), as is the rule in rivers tributary to the Gulf of St. 

 Lawrence. Parr may be moving downstream any time from late spring to autumn, 

 but in Gulf of Maine streams most of them probably make the journey in June and 

 July, being then 5 to 6 inches long. On the other hand it is possible that some may 

 linger in fresh water until 3, 4, 5, or even 6 years of age, as is known to happen in 

 Norway. An occasional male parr may even become sexually mature before visit- 

 ing the sea at all. 



As they near tidewater the parr put off their barred and spotted pattern to 

 assume the silvery coat worn by the salmon during his sojourn in the sea. They 

 are then known as "smolts." After they reach salt water they are found for a 

 time about the shores of estuaries and in river mouths. No doubt the little salmon, 

 too small to sell, that are caught in summer and autumn in weirs at Matinicus 

 Island come from the Penobscot a month or two previous, but they leave the coast 

 in autumn and little is known of their movements during the first winter. Smolts 

 from 7 to 12 inches in length have occasionally been taken in drift nets in Nor- 

 wegian waters and in the North Sea with herring, mackerel, and other fish, sug- 

 gesting that they follow and prey upon the shoals of the latter, but there is no 

 reason to suppose that they move far offshore. However this may be, they grow 

 so rapidly on the abundant diet the sea affords that they usually reach a length of 

 at least 16 inches and weigh anywhere from l]/ 2 to 7 or more pounds by the fol- 

 lowing spring when they reappear on the coast. They are now termed "grilse," 

 distinguishable from the older fish by a more forked tail, more slender form, smaller 

 head, thinner scales, and rounded and more numerous spots that are bluish rather 

 than black. Some of the male "grilse" become sexually mature, and although 

 fewer female salmon mature until older, "grilse" of this sex (fish only one year at 

 sea) accompany the males and the older mature fish up the rivers. In northern 

 Canadian streams grilse are very abundant. This is also the case in the St. Johns 



