Fisheries Behavioral Ecology - Abstracts
Hurst, T.P., M.L. Spencer, S.M. Sogard, and A.W. Stoner. 2005. Compensatory growth, energy storage and behavior
of juvenile Pacific halibut Hippoglossus stenolepis following thermally induced growth reduction. Marine Ecology Progress Series 293:233-240.
Abstract
For fishes settling over wide areas, spatial temperature variation can have a significant
impact on growth rates during the early juvenile period. Size variation within cohorts and across
years will depend on the thermal sensitivity of growth rate, the ability to move to favorable growth
environments, and the potential to compensate for periods of reduced growth. We examined the
growth, behavior and energy storage responses of juvenile Pacific halibut Hippoglossus stenolepis exposed to a thermally induced reduction in growth. Halibut reared for 12 wk at 2°C then acclimated
to and grown at 10°C (delayed treatment) were compared to fish reared continuously at 10°C (controls).
Growth rates at 2°C were 25% of those at 10°C, resulting in a 2.4-fold difference in mass after
12 wk. Following acclimation to 10°C, specific growth rates of delayed fish were 20% higher than
controls. Complete compensation would have required 35 wk, assuming maintenance of observed
growth rate differences between treatments. Rapid growth during the compensation phase was probably
due in part to a reduction in the allocation of energy to lipid storage: length-corrected lipid levels of delayed fish were 14% lower than levels among control fish. Behavioral observations indicated
that growth compensating fish were more active than control fish; this is assumed to reflect increased
foraging activity. However, when presented with food, growth-compensating halibut did not initiate
feeding more rapidly than control fish. The predation and starvation risks associated with increased
activity and decreased energy storage appear to represent trade-offs with rapid compensatory
growth in juvenile halibut.
Last updated
26 April, 2007
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