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Fishery Bulletin 97(2), 1999 



fish has also been reported (MacFarlane and Bow- 

 ers, 1995). Calculations of lipid and protein utiliza- 

 tion for embryogenesis in yellowtail rockfish repre- 

 sent net consumption and conservative estimates 

 because at least some maternal contributions to 

 embryo development occur during gestation (Mac- 

 Farlane and Bowers, 1995). Radio-labelled phos- 

 phatidylcholine injected into the circulatory system 

 of pregnant females resulted in radioactivity in em- 

 bryos, indicating matrotrophy for this phospholipid. 

 The extent to which matrotrophy exists for other lip- 

 ids and protein is unknown. 



As in yellowtail rockfish, total lipid and protein 

 concentrations declined linearly according to stage 

 of development in embryos of shortbelly rockfish, 

 Sebastes jordani (Fig. 2). 



Embryonic development consumed 55% of the pro- 

 tein and 689f of the total lipid present at fertiliza- 

 tion. Thus, both species of rockfish metabolized the 

 same proportion of total lipids, whereas protein was 

 conserved in shortbelly rockfish in relation to yel- 

 lowtail rockfish embryogenesis. It should be noted, 

 however, that yellowtail rockfish had significantly 

 greater protein resources for embryogenesis at fer- 



