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Fishery Bulletin 108(4) 
temperature variation. In studies of juvenile flatfishes, 
this temperature regulation of growth has been referred 
to as the “maximum growth/optimal food condition” 
hypothesis (Karikiri et al., 1991; van der Veer and 
Witte, 1993). Conversely, realized growth rates signifi- 
cantly below 100% indicate that growth is regulated by 
nonthermal environmental factors such as light regime 
or prey availability (Buckley et al. 2006; Kristiansen et 
al., 2007; Hurst et al., 2009). 
Unfortunately, many studies of growth rates in fishes 
are conducted over a limited size range and usually 
within a single life stage. Therefore, these data have 
limited application where growth rates of wild fish are 
tracked over longer time periods or through early life 
history stage transitions. For example, in evaluating 
the mechanisms responsible for variation in survival 
and recruitment, it is critical to determine whether 
growth reductions among wild fish are due to inher- 
ent physiologically based patterns (as appears in post- 
hatch gadids) or are imposed by an unfavorable growth 
environment (Jones, 2002). In another application of 
laboratory data to field studies, the back-calculation 
of hatch dates from estimated temperature-dependent 
growth rates (Lanksbury et al., 2007) could be biased 
if ontogenetic patterns in growth variation are not ac- 
counted for. 
Conclusion 
Growth variation in early life stages can result in body- 
size variation that persists over time and has signifi- 
cant implications for the survival and recruitment of 
marine fish larvae (Houde, 1996; Jones, 2002). Success- 
ful evaluation of the biotic and abiotic factors regulating 
this underlying variation in growth requires detailed 
information on the size- and temperature-dependency 
of potential growth throughout the early life history. 
Identifying the intrinsic patterns in growth-rate allom- 
etry and reductions among preflexion larval Pacific 
cod was based on the integration of experimental data 
on embryos and larvae, — stages generally considered 
in isolation from each other. We suggest that data on 
embryos be routinely incorporated with larval data to 
clarify ontogenetic and temperature-dependent growth 
patterns in the early life history stages of fish. 
Acknowledgments 
We thank T. Tripp, M. Spencer, and B. Knoth for assis- 
tance with fish collection and shipping. Staff and stu- 
dents in the Fisheries Behavioral Ecology Program, 
including L. Copeman, S. Haines, M. Ottmar, P. Iseri, A. 
Colton, L. Logers, E. Seale, and J. Scheingross assisted 
with various laboratory experiments. S. Munch, L. 
Tomaro, A. Stoner, and three anonymous reviewers 
provided helpful comments on earlier versions of this 
manuscript. This research was supported in part by 
a grant from the North Pacific Research Board (no. 
R0605). This is publication no. 248 of the North Pacific 
Research Board. 
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