302 



Fishery Bulletin 105(2) 



D = 800 nm 



/wjy 



250 500 rSO 1000 1250 1500 1750 2000 



D = 900 urn 



250 500 750 1000 1250 1500 1750 2000 



A 



D = 1000 \im 



jA. 



250 500 750 1000 1250 1500 1750 2000 



D = 1000 fim 



!\^ A 



J 200 



•■ 150 

  100 

 -■ 50 



1 |l 



250 500 750 1000 1250 1500 1750 2000 



D = 1100 urn 



k 



^/V*^^/^ 



250 500 750 1000 1250 1500 1750 2000 



D= 1200 urn 



M -A 



200 



■■150 



100 



50 



250 500 750 1000 1250 1500 1750 2000 



D= 1300 urn 



MN -^-A 



T 200 

 150 

 100 

 50 



250 500 750 1000 1250 1500 1750 2000 



100 ■< 



250 500 750 1000 1250 1500 1750 2000 



D = 1500 urn 



4&o^ 



.^A 



200 



150 



 100 



50 



250 500 750 1000 1250 1500 1750 2000 



D = 1600 urn 



i4JX 



-4^ 



■p200 



■■150 



 100 



50 



■^0 

 250 500 750 1000 1250 1500 1750 2000 



Oocyte diameter ((jm) 



Figure 4 



Frequency of oocyte diameter for 10 female Greenland halibut (Reinhardtius hippoglos- 

 soides) arranged in progression of vitellogenic oocyte mean diameter (Dl. Data for non- 

 vitellogenic oocytes (in gray) are plotted in terms of percent frequency, and vitellogenic 

 oocytes (in black) in terms of number of oocytes per gram of ovary tissue. 



estimate of instantaneous natural mortality indepen- 

 dent of age data for a species with an uncertain age 

 structure. Fecundity was higher and eggs were smaller 

 in Greenland halibut from Alaskan waters than the 

 reported values for the Barents Sea. This may be due 

 to a trade-off between number of eggs and egg size 

 (Roff, 1992). Based on the energy invested in annual 

 reproduction (GSI), Greenland halibut mortality (M) 

 appears lower than the values used currently in popu- 

 lation models. 



Acknowledgments 



We thank the scientists of Resource Assessment and 

 Conservation Engineering division of the Alaska Fishery 

 Science Center, and the following fishery observers for 

 ovary collections: J. Bennett, K. Fleming, R. Hutson, C. 

 Hilderbrandt, N. Goddard. A. Randi. and S. Rothamel. 

 D. Kimura, S. McDermott, and D. Nichol provided 

 valuable comments on manuscript drafts. This publi- 

 cation was funded by the Joint Institute for the Study 



