QUAST: BODY WEIGHT, FAT, AND GONADS OF PACIFIC HERRING 



JAN I FEB I MAR  APR H MAY I JUN ' JUL ' AUG ' SEP ' OCT 1 NOV ' DEC 



Figure 5.— Seasonal variation in eviscerated weight as shown by monthly samples of fresh Pacific herring near Auke 

 Bay, AK, given as percentage departure from the weight predicted by the general eviscerated weight/BL regression 

 for these fish (see Figure 4). The percentage departure is given relative to its yearly average to highlight seasonal 

 changes. Data fit by eye. 



on the water content of the musculature, that intra- 

 muscular fat varied seasonally and paralleled the 

 development of visceral fat— water content of evis- 

 cerated body sections for the sexes behaved in an 

 opposite fashion to visceral fat, being highest in 

 April-May and at low levels between June and Octo- 

 ber (Table 3). In contrast to the water content of 

 the musculature, eviscerated weight increased 

 relative to BL after May (Fig. 5). If the increase in 

 eviscerated weight were caused by increased 

 somatic hydration, variation in hydration would 

 have paralleled variation in eviscerated weight, but 

 instead, the values for hydration decreased after 

 May. Some other factor must be responsible for the 

 increased eviscerated weights after May, and a like- 

 ly candidate is fat, because eviscerated weight in- 

 creased over the same period that visceral fat was 

 building. Hart et al. (1940) also described an ap- 

 parent reciprocal relationship between water and 

 oil content in Pacific herring from British Colum- 

 bia, and Love (1970) discussed the same relation- 



Table 3.— Average hydration of musculature as 

 a percentage of wet weight, by month in Pacific 

 herring from Auke Bay, AK. 



ship in Atlantic herring and other fish species with 

 fatty tissues. 



The timing of gonad development, as indicated by 

 seasonal development of gonads, differed in the 

 sexes in Pacific herring from Auke Bay. Males were 



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