. Bulletin of the United States Fish Commission. Fisheries -- United States; Fish-culture -- United States. 376 BULLETIN OF THE BUREAU OF FISHERIES the percentages at the end of each year are as follows: Year II, per cent; year III, per cent; year IV, per cent; and year V, per cent. (Corresponding figures for length, based on year VI are: year I, per cent; year II, per cent; year III, per cent; year IV, per cent; and year V, per cent; see fig. 40.) In comparison with length, the rate of the proportional total weight increase is small during the firs
. Bulletin of the United States Fish Commission. Fisheries -- United States; Fish-culture -- United States. 376 BULLETIN OF THE BUREAU OF FISHERIES the percentages at the end of each year are as follows: Year II, per cent; year III, per cent; year IV, per cent; and year V, per cent. (Corresponding figures for length, based on year VI are: year I, per cent; year II, per cent; year III, per cent; year IV, per cent; and year V, per cent; see fig. 40.) In comparison with length, the rate of the proportional total weight increase is small during the first years of life, for while more than three-fourths of the total length reached by the species is attained at the end of the third year more than five years are required for a similar amount of weight increase. The curves of Figure 40, based on the above percentages, show that after the second year weight increases more rapidly than length. The sudden final acceleration in weight may be due to the small number of individuals in the sLxth year. Of course this rapid increase in. Fig. 41,—Average weight, in ounces, reached by male ( ) and female (— . —) Saginaw Bay herring in dilTerent years of life. The curve based on males and females ( ) involves larger numbers of specimens. Curves are plotted from the grand average weights of Table 34 weight is but an expression of the fact that at first these fish grow chiefly along the horizontal axis and are therefore comparatively slender, while later growth occurs principally along the other axes and the body acquires more depth and thickness. From the point of view of the commercial fisheries it is not profitable to allow the herring, at their present rate of growth, to become much older than 3 or 4 years. The increase in their average weight is about per cent in the third but only per cent in the fourth and per cent in the fifth year; or, stated otherwise, the herring gain on the average ounces in the third but on
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