Fishes of the Western North Atlantic 529 



conspicuously rearward with black as it is in freshwater specimens. The four other 

 Prince Edward Island specimens are intermediate in coloration between these extremes. 

 But none of the Newfoundland specimens (see Study Material^ p. 525) approaches the 

 extreme sea-run coloration, though they were taken only one mile upstream from where 

 the river empties into the open Gulf of St. Lawrence." 



It seems, as Smith remarked a century and a quarter ago {60: 354, '})^^^ that the 

 most silvery of the Salters are the ones that pass their marine sojourn in the saltiest water 

 and are taken soon after they leave the stream mouths, whereas the least silvery are 

 those that remain within the estuaries, where the water is more or less brackish. 



When the Salters re-enter fresh water, the back and the upper sides soon darken, 

 the silver of the sides fades out, the pale spots on the sides become more intensely 

 orange, the pectoral, pelvic, and anal fins gradually assume the white-black and orange- 

 to-reddish pattern typical of the freshwater fish, the pure white on the lower part of the 

 sides develops a pinkish band in the males, and the belly tends to become gray. Brook 

 Trout fresh-run from the estuary that were contained in pens in the Moser River under- 

 went this alteration between July 15 and September 10, by which date "it was impos- 

 sible to distinguish sea and fresh water trout by color" (Wilder, yS: 174). And the 

 Salters of Cape Cod may lose their sea coloring within 10—14 days after they re-enter 

 fresh water (9 : 8). 



Size. Brook Trout are about 14 or 15 mm (0.56 in.) long when hatched, and there 

 is no reason to suppose that fontinalis fry destined to run down into salt water differ 

 in size at hatching from those that are destined to spend their life in fresh water. 

 Two or three years later, when they migrate downstream, the Salters average about 

 175 mm in length (6.9 in.) in Nova Scotian waters, and about 178 mm (7 in.) on the 

 coast of western Newfoundland,^* a growth rate that agrees closely with S.c^ inches at 

 two years and about 8 inches at three years as reported for hatchery fish (perhaps 

 more abundantly fed) at Caledonia Springs Hatchery, New York (29: 312). 



The maximum size to which /o«//««/w grow in fresh water varies from one stream 

 to another and from one pond or lake to another, even within short distances. A 1.5- 

 pound fish, generally speaking, is a large one in any small water, and a 5-pound fish 

 is a large one in most of the larger waters. In some northern streams, however, and in 

 northern lakes, many of them grow far larger than that. Goode et al., for example, men- 

 tion one of 1 1 pounds that was received by Louis Agassiz from the Androscoggin 

 River in northwestern Maine in i860, and a Rangeley Lakes fish that weighed 10 

 pounds after it had been in captivity for three years (26: 499, 500). Kendall found 

 records of more than 60 fish heavier than 9 pounds, 15 of lo-ii pounds, and 4 

 of 1 2-1 2.5 pounds, which had been taken at one time or another in the Rangeley Lakes, 

 Maine (45: 90-95); he also reported one of 1 1 pounds for Belgrade Lake, Maine, and 

 one of ten pounds for Square Lake, Maine. The record (weighed) weight is 14 pounds 

 8 ounces, for one caught July 1 9 1 6 by J. W. Cook in the Nipigon River, tributary 

 to the north shore of Lake Superior, where Hewitt (j^: 170) also took one 26 inches 



17. Information contributed by A. R. Murray, Fisheries Research Board of Canada. i8. Ibid. 



