112 
BULLETIN OF THE BUREAU OF FISHERIES 
Winge (1915, p. 11), working with the cod, concluded that there was a close 
agreement between the growth of the scales and that of the fish. He selected 7 
scales from each of 4 fish (31 to 43 centimeters long) at the time of tagging and again 
1 to 2 years later, when these fish were recaptured (when 43 to 66 centimeters long.) 
As a result he found that each of the scales examined from the same fish increased in 
size in approximately the same proportion and that in each case the “increments of 
growth in scale and cod, respectively, are very nearly directly proportional.” How- 
ever, Huntsman (1919, pp. 65-66) points out that the scales of Winge’s smallest cod 
had grown somewhat faster than the fish, while the scales of the larger cod had grown 
proportionately less than the fish, and states that “these results indicate a definite 
change in the growth of the scale relative to the growth of the fish, namely, an early 
more rapid and a later less rapid growth. This is similar to what I have found for 
other fish by a different method.” Huntsman (1918a) discusses the errors resulting 
from calculating lengths from the annuli formed on the scales and describes a method 
for reducing the degree of error. Duff (1929, p. 10) concurs with Huntsman’s views, 
for he found that the rate of growth of the cod and its scales are not equal but vary 
throughout the year, and that the scales of small fish were longer in. proportion to the 
length of the fish than the scales of large cod. 
Lee (1912, p. 15) found that on herring and haddock scales the calculated lengths 
attained at 1 year of age were larger for the younger fish than for the older. For 
example, the scales from one lot of haddock made it appear that on their first birth- 
day the 2-year-old fish averaged 18.3 centimeters; the 3-year fish, 17.6 centimeters; 
the 4-year fish, 16.6 centimeters; and the 5-year fish, 15.1 centimeters. This same 
progressive decline obtained for the second and succeeding years, making it seem that 
with increasing age the fish showed a decreasing rate of growth in the calculated 
values for each year of their lives. This is called by Lee “the phenomenon of appar- 
ent change in the growth rate.” Thompson (1923, p. 15) concurs with the findings 
of Lee in regard to the haddock, for he found that while there was little error if 
1 + -year old haddock were used in calculating the size attained at 1 year of age the 
error increased as the scales from older fish were examined. 
Whether the rate of growth calculated from cod scales will show a progressive 
decrease, as was found with the scales of haddock and certain other fish, is not 
definitely known at present. According to the sample of scales given in Table 42, 
there appears to be a slight tendency of this sort which, although not shown by the 
averages, manifests itself in the 6, 7, and 8 inch values of the III, IV, and V year 
classes. 
Table 42. — Length attained at the completion of the first growth zone as calculated from the scales of 
Nantucket Shoals cod of various ages caught during the summer of 1923 
Calculated length in inches at completion of first growth zone 
Age of scale 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
Total 
Average 
Number 
Number 
Number 
Number 
Number 
Number 
Number 
Number 
Number 
Number 
Number 
Number 
Inches 
TT 
5 
8 
1 
1 
15 
7. 86 
TTT 
3 
5 
16 
17 
29 
19 
9 
4 
5 
107 
6. 93 
IV 
i 
8 
28 
81 
100 
65 
23 
21 
10 
i 
1 
339 
7. 18 
V 
2 
11 
22 
15 
6 
8 
10 
3 
77 
7. 18 
vr 
2 
4 
3 
7 
4 
1 
i 
22 
7. 91 
VTT 
1 
3 
1 
2 
1 
8 
7.87 
VTTT 
1 
1 
2 
8. 00 
TX 
1 
2 
3 
5.66 
