Sewall and Rodgveller: Changes in body composition and fatty acid profile during embryogenesis of Sebastes maliger 
215 
Figure 5 
Percentage of individual fatty acid (FA) masses lost during embryogenesis of 
quillback rockfish ( Sebastes maliger) larvae. Percentage mass losses represent 
differences between average FA masses per larva of four early embryonic samples 
and four hatched larval samples, in relation to masses present in early embryonic 
samples. Each sample was a composite of hundreds of larvae from the same 
parent (n = 8 maternal females). Dashed line indicates difference in total lipid 
mass between embryos and larvae in relation to lipid mass in embryos. 
cannot be generalized to developing rockfish embryos 
and larvae. Although we did not attempt to directly 
assess the influence of specific FAs on larval survival, 
our results show FAs are depleted at different rates 
during embryogenesis. When used in conjunction with 
data on total lipid levels, the relative abundances of 
specific conserved FAs of known metabolic importance 
(e.g., 20:4n-6) may be useful in assessing the condition 
of embryos and preparturition larvae collected from 
wild-caught female rockfish. 
Body composition and energy use 
Comparisons with other studies of rockfish revealed sub- 
stantial diversity in the body compositions and energy 
use patterns of embryos from different Sebastes spe- 
cies — even after allowing for differences in methods 
and the high degree of variability in the compositional 
data. For example, the early stage quillback rockfish 
embryos studied here had lower lipid (-6.7%) and protein 
(-14.1%) wet tissue concentrations than those found by 
Eldridge et al. (2002) for late vitellogenic eggs and early 
embryos of yellowtail rockfish (S. flavidus) (-12.8% and 
-21.0%, respectively). Quillback rockfish embryos had 
lower energy density on a dry mass basis (-24.3 kJ/g) 
compared with the yellowtail rockfish embryos (-27.1 
kJ/g), but because of their larger dry mass, the embryos 
of quillback rockfish had much greater total energy per 
individual (3.40 J) than those of the yellowtail rockfish 
(-1.06 J). 
The patterns of decline in lipid and protein in quill- 
back rockfish differed somewhat from those reported 
by MacFarlane and Norton (1999) for yellowtail rock- 
fish. They found that lipid as a proportion of wet mass 
declined 68% and protein decreased by 77%, whereas 
we found that lipid declined 51% and protein declined 
41%. The smaller decreases in lipid and protein con- 
centration we found may be an artifact of the different 
ranges of development observed (i.e., our study did not 
include data from unfertilized oocytes or the earliest 
stage-1 embryos, when protein and lipid levels were 
likely higher). The slightly greater decreases in protein 
concentration than in lipid concentration reported for 
yellowtail rockfish — opposite to the pattern we found 
with quillback rockfish — illustrates the high degree 
of variability among rockfish species. The results of 
MacFarlane and Norton (1999) for shortbelly rockfish 
(S. jordani ) followed a pattern similar to ours, with 
lipid decreasing by 68% and protein by 55%, indicating 
greater conservation of protein by shortbelly rockfish 
