Fishes of the IVestern North Atlantic 515 



cording to Grainger's age determinations {28: 341), the great majority of 1,566 

 specimens measured during 1948, 1950, and 1951 were 300-350 and 650-695 mm 

 long, with a few longer than 795 mm; these sizes correspond roughly to ages of 9-10 

 and 19-24 years, respectively, with a few somewhat older still. A similar picture 

 emerges for the northwestern part of Hudson Bay, where only seven fish among 96, 

 for which Sprules determined the ages, were less than seven years old whereas 70 "/o 

 were between 8 and 11 years old {^2\ 6, tab. i); and while the survival rate dropped 

 off abruptly after 11 years, one of the specimens was 22 years old and weighed 16 

 pounds. Thus, the sea-run alpinus are not only much longer-lived than the sea-run 

 fontinalis but their rate of survival is much higher. 



Spawning and Reproduction. Spawning may take place either in streams or in lakes, 

 at depths ranging from within a foot or two of the surface down to 15 feet or so. 

 Sprules reported that, in lakes, the eggs are deposited on gravel beds in 6-15 feet of 

 water {62: 12). In rivers they are laid in shallow pools below rapids in about two feet 

 of water, where the current is strong and the bottom is covered mostly with "round 

 stones just too large to be carried along by the water." Here the fish lie "apparently 

 motionless, . . . and . . . return to the same places almost immediately after being 

 frightened away" (Weed, ^2: 132). The females of the landlocked fish of Lake 

 Windermere, England, have been described as making shallow depressions for the 

 reception of their eggs in the gravel or stony bottom (Jackson in 61 : 847), as other 

 salmonids commonly do, but this habit has not been recorded for the sea-running 

 populations. 



Normally, alpinus, like fontinalis, spawn in fresh water, but Weed has written that 

 "the fishermen along the Labrador coast believe that some of the sea trout spawn in 

 the sea" {j2: 132); and he reports the capture in salt water of females with free eggs 

 in the oviducts. There seems to be no reason, however, to believe that any eggs would 

 survive that might be deposited in salt water. 



Arctic Charr have been described as spawning for the first time in Spitsbergen 

 when they are 5+ years old {li: 8), in Icelandic waters probably at about 6 years 

 (Saemundssen in 28: 363), and around Novaya Zemlya at 6 or 7 years of age {yg: 

 69, 70), but not until about their 12th year or later in Frobisher Bay, Baffin Island 

 {28: 363). Thus, if these estimations are even approximately correct, alpinus is very 

 much slower th.a.n fontinalis in reaching sexual maturity (p. 531). It appears also from 

 evidence assembled for Baffin Island by Grainger {28: 363) that spawning may not 

 be a regular annual event for every adult, though it seems hardly likely to be a bien- 

 nial one regularly, as has been suggested for Arctic Charr of Novaya Zemlya (yg). 



Labrador females of 465-665 mm contained 2,173-7,223 ovarian eggs in dif- 

 ferent stages of development, a western Greenland female of 520 mm contained 4,620 

 (28: 364; 59: 69), and Novaya Zemlyan fish averaged about 3,500 eggs (jg: 69-70). 

 The eggs of freshwater Arctic Charr of Scandinavia are 4-5.5 mm in diameter. I 

 have found no record of the size of naturally spawned eggs of the sea-run popula- 

 tions of alpinus. 



33* 



