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Fishery Bulletin 97(2), 1999 



ship to growth or survival potential, ease or cost of 

 analysis (or both), operational feasibility, or the abil- 

 ity to assess adequate numbers of replicates for sta- 

 tistical validity often diminish their utility in rou- 

 tine assessments of reproductive success. Consider- 

 ation of when, during egg and embryonic develop- 

 ment, valid estimates can be made is also critical to 

 accurate assessment of success. Ideally, evaluation 

 at hatching or birth would provide the most accu- 

 rate determination of health and survival potential, 

 but this event is of very short duration, and obtain- 

 ing enough individuals to characterize a population 

 or species is difficult. 



The nutritional status, or energy content, of em- 

 bryos and lai-vae has a clear relationship to growth 

 and survival potential because the amount of meta- 

 bolically available energy establishes the duration 

 of survival in the environment until adequate food 

 becomes available. Starvation during the early stages 

 of development has been considered a major source of 

 mortality or reduced fitness and may contribute to fluc- 

 tuations in year-class strength (May, 1974; Shepherd 

 and Gushing, 1980; Rissik and Suthers, 1996). 



Low and unstable abundance of prey typifies the 

 environment off central California during winter and 

 early spring (Ainley et al., 1993), the period when 

 many species of viviparous rockfish give birth (Wyllie 

 Echeverria, 1987). Pelagic larvae rely on endogenous 

 nutritional reserves to supplement sparse forage until 

 the biologically productive annual upwelling season 

 begins, usually in late March or April (Bakun, 1975). 



This study describes protein and lipid metabolism 

 during embryonic development in two species of the 

 viviparous genus Sebastes. A procedure is presented 

 to estimate the lipid and protein composition at par- 

 turition, or birth, which provides a measure of nu- 

 tritional status and thus may be related to the prob- 

 ability for survival at the earliest free-living stage. 

 Nutritional status at birth is presented for yellow- 

 tail rockfish and three populations of shortbelly rock- 

 fish (Sebastes Jordani), thereby providing compari- 

 sons between congeners occupying different ecologi- 

 cal niches and among populations separated spa- 

 tially. These data are the first documentation of lipid 

 class composition in eggs, embryos, and larvae of a 

 viviparous marine teleost. 



Materials and methods 



Female S. flavidus and S. jordani were obtained fi-om 

 January to March, the period of reproductive devel- 

 opment spanning late vitellogenesis to parturition, 

 at locations off the central California coast. Yellow- 

 tail rockfish were captured by hook-and-line at 



Cordell Bank (38°01'N 123°25'W), a marine bank 37 

 km west of Pt. Reyes, at depths ranging from 50 to 

 150 m. Shortbelly rockfish were collected by trawl at 

 150 to 200 m depth in the proximity of three subma- 

 rine canyons: Bodega Canyon (ca. 38°13'N 123°22'W), 

 Pioneer Canyon (ca. 37'^24'N 122-52'W), and Ascen- 

 sion Canyon (ca. 37°01'N 122°25'W). Fish were held 

 on ice for up to 12 h until examination. Morpho- 

 metries (e.g. standard length; body and liver weight) 

 were recorded and ovaries excised, weighed, and 

 stored at -70°C. The stage of oocyte or embryonic 

 development was identified by microscopy according 

 to the classification scheme of Yamada and Kusakari 

 ( 1991) for Sebastes schlegeli (Table 1). 



