514 Memoir Sears Foundation for Marine Research 



of locality {28: 348). Fish of 600 mm, "for example, are found In all age groups 

 between 13 and 24 winters." The over-all picture for the western North Atlantic area 

 as a whole, and for Hudson Bay, Is of a very long-lived and slow-growing fish, with 

 the relationship between age and size averaging roughly as shown In Table vii. 



Dahl's observation that such of the 



Table VII. 



Age 

 (years) 



4 



5 



6 



7 



Approximate Average Lengths of 4- to 

 16-year-old S.alpinus 



Fork Length 

 (mm) 



Age 

 (years) 



90-201 

 130-382 

 123-408 

 172-449 



8 268-557 



9 337-570 



10 363-584 



II 

 12 



13 

 14 

 15 

 16 



Fork Length 

 (mm) 



414-626 

 425-625 

 484-656 

 510-636 



553-571 

 557-767 



alpinus of Spitsbergen as run down to the 

 sea after four years in fresh water grow 

 larger than those that remain In fresh 

 water for two or three years (Table viii) 

 suggests that the longer an alpinus Is a 

 parr, the more rapid is Its subsequent 

 growth In the sea. 



The populations of alpinus that re- 

 main permanently in fresh water grow 

 more slowly than those of the same region 

 that go to sea. Sprules {62 : 9), for example, has pointed out that landlocked alpinus 

 in the northwestern Hudson Bay region average only about 12.3 inches and about 

 nine ounces when ten years old, whereas the sea-run Arctic Charr of that same age 

 average about 20.6 Inches and 3.75 pounds. In western Greenland, similarly, the 

 landlocked fish found above falls are smaller than 

 those that are sea-run {^2: 294; jp: 74). 



Survival Rate and Longevity. The great ma- 

 jority of sea-run alpinus of northeastern Labra- 

 dor are between 7 + and 1 2 + years old, with a 

 pronounced peak at 8 + to 1 1 + years and a rapid 

 falling off after 1 3 -h years, as appears from Table 

 IX. Also, the mean age (in years) of the samples 

 studied showed an Increase from south to north 

 as follows: Adlok, 8.5; Nain, 8.9; Okkak, 10.2; 

 Hebron, 10.5; Ramah, 10.5. 



In Spitsbergen waters, according to Dahl, 

 84 "/o of the fish examined were between about 

 4—6 years old and about 7-9 years old, including 



2—4 years passed as parr in fresh water (jj: 6); and an occasional fish had even 

 spent as much as eight years in fresh water. In Frobisher Bay, Baffin Island, ac- 



Table VIII. Lengths (mm) of Sea-run 

 S. alpinus of Different Ages, as Related to 

 the Number of Years Spent in Fresh Wa- 

 ter Previous to their First Migration to 

 Salt Water* 



■ Age at First iVIigration ■ 



Years 

 in sea 



2. 

 3- 

 4- 



5- 

 6. 



2 yrs. 



340 



446 

 516 

 590 



* After Dahl, 11: 



3 yrs. 



361 



377 

 450 



538 

 603 



4 yrs. 



390 

 403 

 487 

 570 

 610 



Table IX. Number of Arctic Charr of Different Ages among 487 Fish from the Coast 

 of Labrador, Adlok to Ramah Combined f 



Age (years)* ... 7-1- 8 + 



No. of fish 47 69 



Percentages .... 10 14 



f From Andrews and Lear, 2: 849, tab. 3. 



9. 

 108 

 22 



10 + 



99 

 20 



11 + 

 66 



13 + 

 30 

 6 



12 + 



44 

 14 9 



* Based on a study of the otoliths, 



14 + 



5 

 I 



15 + 

 5 

 I 



16 + 

 2 



0-3 



