Theilacker and Porter: Condition of Theragra chalcogramma in the Gulf of Alaska 



339 



4.5 5.5 65 7.5 8.5 



10 - minute net treatment standard length (mm) 



6 5 



§ 6.0 i- 



5.5- 



4.5- 



4.0 



3.5 4.0 4.5 5.0 55 6.0 6.5 



Preserved standard length after 10 - minute net treatment (mm) 



Figure 5 



Size of fed walleye pollock, Theragra chalcogramma, measured 

 live in the laboratory related to (A) their size after preservation 

 in Bouin's fixative, to (B) their live size after a 10-min treatment 

 in a net, and to (C) the size of live larval walleye pollock treated 

 in a net for 10-min (NL SL [see explanation in Footnote 5 of 

 Table 3]) related to their preserved size in Bouin's fixative after 

 the net treatment. Regression equations are found in Table 3. 



Shrinkage in preservative after net treatment Correction for field-captured size 



Net-treated larvae shrank an additional 11.8% after 

 being preserved in Bouin's preservative (Table 3). 

 Shrinkage was constant over the size range treated 

 (5.52-8.24 mm SL, re=18; Fig. 5C). Additional shrink- 

 age of net-treated larvae in Z-Fix was 3.6% (5.36— 

 7.84 mm SL, n=35; Table 3) and in 5% formalin was 

 9.7% (4.48-8.40 mm SL, n=50; Table 3). 



The elapsed time from larval collection to preserva- 

 tion and the preservative type determine which two 

 equations in Table 3 are needed to adjust field-col- 

 lected and preserved size to the equivalent live size. 

 To examine the accuracy of the regression equations 

 for estimating the live length of field-collected lar- 

 vae (Table 3), we measured the live size of 20 larvae, 



