TSrUTRITIVE VALUE OF FISH AND SHELLFISH 



521 



This table shows that in addition to the variations of fish in different 

 streams there are certain general changes that are obvious. In the 

 first place the chinook or king salmon in Alaska, v/ith the exception of 

 the Chignik River, is not as rich in oil and consemiently in fuel valiie 

 as the salmon from the canning districts in the United States. The 

 chinooks caught on Puget Sound average about the same in food 

 value as those caught in the Columbia River. However, there is no 

 careful grading system in effect in the Puget Sound district such as on 

 the Columbia River, and so we have no class of selected No. 2 grade, 

 for instance, that compares with No. 2 chinooks on the Columbia 

 River. 



A detailed study was made of the composition of chinooks caught at 

 Astoria, near the mouth of the Columbia River, with those caught 200 

 m.iles from the mouth, and it was found in a general way that there 

 was little, if any, variation in fuel value in -this 200-mile stretch of 

 river. A further study of the composition of the three different 

 grades on the river showed that in a general way the grading that was 

 done for color seemed also to show a certain correlation in the matter 

 of the percentage of oil, as the fuel value seemed to run in proportion 

 to the grading, the primary object of which was to select the brightest- 

 colored fish for the higher grades. On the one hand, analyses of white- 

 fleshed fish on Puget Sound, as compared with red-fleshed fish taken 

 at the same time and at the same place, showed that there was little, if 

 any, difference in the fat content between the red and the white 

 varieties, at least in that particular locality; on the other hand, the 

 white-fleshed chinooks on the Columbia River seemed to run about the 

 same as a No. 3 grade chinook — namely, relatively low in oil as well as 

 poor in color. However, more work will have to be done along this 

 line to prove conclusively that color and food value have any necessary 

 relationship. 



Table 15. — Variation in the composition of individual California mackerel 

 {Scomber japonicus) , based upon analysis of the edible portion on the fresh basis 



Num- 

 ber 

 ana- 1 



lyzcd i 



Description 



Males 



Females. 



Male, spent 



Female, si)ent- 

 do_ 



do_ 



Female, full. 



do 



Males, full-- 



Female 



do 



do 



do 



-do 



Male. 



do.. 



Female - 



do._ 



Male... 



Average 

 weight, 

 grams 



526 



546 

 511 

 511 



582 



596 



590 



624 



823 



1,135 



1,220 



538 



568 



568 



625 



682 



1,022 



1,079 



1,193 



1,332 



1. 333 



538 



625 



681 



838 



938 



Date 



1918 



Oct. 25.. 

 ...do__-. 

 ...do.-.. 



Nov. 17 

 ...do 



1919 

 Aug. 7 

 ...do... 

 .._do_._ 

 ...do... 

 ...do... 

 Aug. 11 

 ..-do___ 

 Nov. 18 

 _-do._. 

 ...do... 

 ...do__. 

 .-do,.. 

 ..do... 

 ...do._- 

 ...do__. 

 ...do... 

 ..do_-_ 

 Dec. 

 ...do 



10 



..do. 

 ..do. 



Total 



solids 



Per cent 

 25.92 

 26.20 

 31.71 

 24.35 

 24.89 



28. 16 

 26.83 

 28.03 

 28. 18 

 32.65 

 30.36 

 30.69 

 28.57 

 32. 57 

 32.31 

 34.21 

 32. 96 

 29.33 

 37.67 

 37.25 

 39.84 

 41. 05 

 30. 65 

 33.00 

 33.99 

 37.48 

 30.31 



Fat 



Per cent 

 1.27 

 .85 

 7.88 

 .41 

 .85 



3.50 

 2.91 

 3.87 

 4.48 

 9.81 

 6.35 

 7.50 

 5.25 

 9.78 

 9.34 

 11.68 

 10.69 

 6.86 

 15.45 

 15.84 

 18.93 

 20.32 

 8.41 

 10.32 

 12.35 

 17.78 

 7.77 



Protein 



(NX 6.2.5) 



Per cent 

 23.50 

 24.31 

 22.88 

 23.06 

 23.37 



23.56 

 22.81 

 23.08 

 21.81 

 2L44 

 23.06 

 21.87 

 22.38 

 21.88 

 22.19 

 22.88 

 22.06 

 21.68 

 20.81 

 20.44 

 20.31 

 20.44 

 22.00 

 21. .56 

 21.56 

 21. 25 

 21. .56 



Ash 

 (inor- 

 ganic 

 matter) 



Per cent 

 1.27 

 1.52 

 1.34 



1.41 

 1.37 



1.45 

 1.47 

 1.47 

 1.44 

 1.32 

 1.40 

 1.31 

 1.56 

 1.43 

 1.23 

 1.35 

 1.37 

 1.33 

 1.28 

 1.20 

 1.04 

 1.04 

 1.23 

 1.31 

 1.35 

 1.34 

 1.52 



Fuel 

 value 



per 

 pound 



Calories 

 491 

 488 

 758 

 446 

 471 



586 



547 



592 



595 



813 



697 



722 



638 



820 



807 



919 



.861 



695 



1,039 



1,048 



1,177 



1, 237 



764 



836 



922 



1, 145 



729 



