File:Bulletin of the Bureau of Fisheries (1914) (14761917994).jpg

Identifier: bulletinofbureau341914unit (find matches)
Title: Bulletin of the Bureau of Fisheries
Year: 1904 (1900s)
Authors: United States. Bureau of Fisheries
Subjects: Fisheries Fish culture
Publisher: Washington, D.C. : Govt. Print. Off.
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Smithsonian Libraries

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uaria on June 24. From June 27the feeding record shows their treatment tillthey died or were taken out, August 22. Inthe beginning the fish in aquarium no. 2 were fed sparingly, but as it was learned thatthey could live on very little, feeding was practically abandoned during the month ofAugust. In all cases the fish in aquarium no. 1 were fed daily all they would eat, whilethose in no. 2, even when fed, were never satisfied. For some unaccountable reason allof the well-fed fish died on August 6, while one of the starving fish died August 5.Careful watch was kept on the growth of the scales, but no difference whateverwas noticeable in the formation of annuli. Any difference in growth was so small asnot to be reckoned with. (PI. Lviii, fig. 25, 26.) These results appear to offer conclusive evidence that feeding habits have no in-fluence upon the formation of annuli. Other possible factors yet untested are theinfluence of temperature and the presence of lime salts in the food and water.
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2 3 Age in years Fio. 6.—Occurrence of pigfish at different ages. SCALE OBSERVATIONS OF THE SQUETEAGUE AND PIGFISH. 321 The method of determining the probable length of life and spawning time of thepigfish was the same as that pursued for the squeteague. The survival of the greatmajority of pigfish through two years, followed by a sudden and great diminution innumber, suggests the conclusion arrived at by Gilbert (1913) for the Pacific coast salmon,i. e., that this is the age of sexual maturity and that as a general rule they perish afterthis time. A glance at text figure 6 shows that out of 167 fish observed, only one reachedthe fourth year; 17 reached the third year, while 75 and 74 reached the ages of i and 2019181716151413^ 12 s .111 I 10 I «I 7 i K ji - 4J^ -y^ 4 \ -^Z-X t I 7 a t X t J^^t 4 -^ V \ 7 X t t It x t tl A ^ 4-- tX ^r—,t A t^^ t^X -. t ^^^ t AAA 7tt 7 ^X^^ALA^ t^ -^ t Z sSZ V t-^-^ ^ ;r N^ Xa Ab V ^^ 8 9 10 11 12 13 14 15 16 17 13 19 20 21 22 23 24 25 25 27 28 Le

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