207 
Changes in body composition and 
fatty acid profile during embryogenesis 
of quillback rockfish ( Sebastes maSiger) 
Cara J. RodgveSSer 
Email address for contact author: Fletcher.Sewall@noaa.gov 
National Marine Fisheries Service, NOAA 
Alaska Fisheries Science Center 
Auke Bay Laboratories 
Ted Stevens Marine Research Institute 
17109 Pt. Lena Loop Road 
Juneau, Alaska 99801 
Abstract — We investigated develop- 
mental changes in the body composi- 
tions and fatty acid (FA) profiles of 
embryos and preparturition larvae 
of the quillback rockfish ( Sebastes 
maliger). Comparisons of proximate 
composition data from early-stage 
embryos with data from hatched 
preparturition larvae taken from 
wild-caught gravid females indi- 
cated that embryos gain over one- 
third their weight in moisture while 
consuming 20% of their dry tissue 
mass for energy as they develop into 
larvae. Lipid contributed 60% of the 
energy consumed and was depleted 
more rapidly than protein, indicating 
a protein-sparing effect. Oil globule 
volume was strongly correlated with 
lipid levels, affirming its utility as 
an indicator of energetic status. FA 
profiles of early embryos differed 
significantly from those of hatched 
larvae. Differences in the relative 
abundances of FAs between early 
embryos and hatched larvae indicated 
different FA depletion rates during 
embryonic development. We conclude 
that some metabolically important 
FAs may prove useful in assessing 
the condition of embryos and prepar- 
turition larvae, particularly 20:4n-6, 
which cannot be synthesized by many 
marine fish and which is conserved 
during embryogenesis. Variability 
in body composition and energy use 
among rockfish species should be 
considered when interpreting any 
measures of condition. 
Manuscript submitted April 14, 2008. 
Manuscript accepted November 19, 2008. 
Fish. Bull. 107:207-220 (2009). 
The views and opinions expressed 
or implied in this article are those 
of the author and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Fletcher F. Sewall (contact author) 
The nutritional condition of fish 
during their early life histories may 
play a major role in determining the 
strength of year classes because larvae 
must have energy stores sufficient to 
ensure survival to first feeding. The 
survival rates of early planktonic 
rockfish larvae may be influenced 
by differences in the amounts and 
use of endogenous protein and lipid 
sources during embryonic develop- 
ment (MacFarlane and Norton, 1999). 
Despite this potential importance, 
little is known about the biochemis- 
try of developing rockfish embryos 
and larvae. Because utilization of 
lipid and protein may vary by species 
(e.g., MacFarlane and Norton, 1999) 
and life history stage (e.g., Norton 
et al., 2001), it is important to exam- 
ine these variables by species at the 
appropriate life stage. 
Quillback rockfish (Sebastes ma- 
liger) are a long-lived, slow-growing 
species of commercial importance, for 
which biochemical data on early life 
stages are lacking. Like other rock- 
fish species of the genus Sebastes, 
they bear live young, and embryos 
(as post fertilization, prehatching in- 
dividuals with the chorion intact) de- 
velop and hatch as larvae (individuals 
free of the chorion envelope) inside 
the maternal female before being ex- 
truded (Yamada and Kusakari, 1991). 
Survival during the larval phase can 
be vital in determining the eventu- 
al size of a rockfish cohort (Ralston 
and Howard, 1995). The utilization 
of lipids is of particular importance, 
as triacylglycerols (TAGs) and polar 
lipids (mainly phospholipids) may be 
the primary energy sources during 
rockfish embryogenesis (MacFarlane 
and Norton, 1999). Endogenous TAG 
is thought to reside mainly in an oil 
globule, the volume of which was iden- 
tified as a main correlate of survival 
of black rockfish larvae (S. melanops ) 
(Berkeley et al., 2004). In that study, 
total lipid concentration was not re- 
lated to oil globule volume (OGV) or 
later larval survival; however, lipid 
levels have been correlated with sur- 
vival for many other fish species (re- 
viewed in Kamler, 1992). Research 
with wild-caught shortbelly rock- 
fish (S. jordani) (pre-flexion larvae 
through juvenile stages) has indicated 
that the relationship of TAG to total 
lipids, and the usefulness of TAG as 
an indicator of nutritional status, 
depends upon life stage (Norton et 
al., 2001). Given this variability, it 
is unclear what trends may occur in 
total lipid levels and oil globule TAG 
reserves in developing quillback rock- 
fish embryos. If OGV can be shown to 
be a reliable indicator of lipid levels, 
using this measurement would rep- 
resent a substantial savings in time 
and cost as compared with analytical 
chemistry techniques. 
Embryos and larvae of quillback 
rockfish are likely incapable of syn- 
thesizing essential fatty acids (EFAs), 
either entirely or at a rate which will 
meet their metabolic needs for growth 
and survival, as is the case for adults 
of other fish species (e.g., as reviewed 
