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Fishery Bulletin 93(2). 1995 



Vitellogenesis 



Early / Late 



/ F / Embryo / Spent 



Figure 1 



Annual ovarian reproductive cycle and monthly tissue wet 

 weights for gonad, liver, muscle, and mesenteric fat of yel- 

 lowtail rockfish, Sebastes flavidus. Values are means ±SE 

 in grams adjusted by ANCOVA for variations in fish size. 

 Temporal sequence of ovarian maturation stages are shown 

 in bar across the top; recrudescence or early development 

 (Dev), early and late vitellogenesis, fertilization (F), em- 

 bryogenesis (Embryo), and spent. 



ductive cycle in both sexes (Fig. 1). These somatic 

 tissues increased in mass during the summer and 

 remained elevated into fall. Females accumulated 

 significantly more mesenteric fat, liver, and muscle 

 than did males (P<0.001). Declines in female somatic 

 tissues in the fall and winter, during late vitellogen- 

 esis and embryogenesis, were inversely related to the 

 accretion of ovarian tissue. 



Temporal changes of ovarian tissue components 

 followed a pattern similar to ovarian mass (Fig. 2). 

 Protein and lipid increased 22-fold and 7-fold, respec- 

 tively, from vitellogenesis in October to early gesta- 

 tion in January. Although glycogen showed a signifi- 

 cant increase (P<0.001 ), quantities were always small, 

 representing less than 1% of ovarian mass. Ash and 

 water profiles reflected increased ovarian mass. At 

 maximal size, water accounted for about 70% of ovary 

 mass. Fluctuation in the masses of testicular compo- 



Gonad 



Figure 2 



Monthly lipid, protein, glycogen, ash, and water content 

 in gonad tissues of yellowtail rockfish, Sebastes flavidus, 

 during one reproductive cycle. Values are means ±SE in 

 grams on a wet weight basis. Missing male values are due 

 to small testes size. 



nents were insignificant compared with ovarian 

 changes. In many cases, testicular quantities were in- 

 sufficient to perform analyses of all constituents. 



Dynamics of liver components were dissimilar across 

 the reproductive cycle and between sexes (Fig. 3). Lipid 

 and protein increased from late spring into summer in 

 both sexes; the greatest net gain in female lipid was 

 between July and August. In August, lipid was about 

 40% of liver mass, whereas protein contributed 10—15%. 

 After August, female liver lipid decreased, but protein 

 remained elevated during vitellogenesis until January. 

 Significantly more liver protein was retained in females 

 than in males from October to January (P<0.001 ). Both 

 female and male liver glycogen followed a temporal 

 pattern of a bimodal increase in the spring and sum- 

 mer with a decrease in the winter. The quantity of gly- 

 cogen was only a small portion of total liver weight. 

 Water in female liver accounted for a large portion of 

 retained liver mass relative to males during late sum- 

 mer and fall (September through December). 



