Aquatic Sciences Meeting, Albuquerque 2001

SS42 American Fisheries Society/ASLO Joint Session: Scaling Fisheries From Egg to Adult and Back Again (Spatial and Temporal Connections)

Date: Wednesday, February 14, 2001, Time: 3:45:00 PM

Location: Sandia/Santa Ana

McConaugha, J, R, Old Dominion University, Norfolk, USA, jmcconau@odu.edu

McConaugha, C, S, Old Dominion University, Norfolk, USA, cmcconau@odu.edu

PHENOTYPIC PLASTICTY IN LIFE HISTORY STRATEGIES OF DECAPODS

Phenotypic plasticity allows a genotype to exhibit different phenotypes in response to changing environmental or population dynamics. Phenotypic plasticity should act to optimize life history strategies including reproductive output. There is increasing evidence from both fisheries dependent and independent surveys, that populations of the brachyuran crab Callinectes sapidus respond to short-term declines in abundance by reducing age and size at maturity. Given the strong linear relationship between size and fecundity in this species (Prager, et al., 1990) an obvious trade-off of reduced size is a reduction in fecundity per brood. Simple models suggest that under high rates of juvenile mortality, early maturation is favored even with reduced brood size. Age determination of female crabs, based on the histological measure of lipofuscin accumulation in the olfactory lobe of the brain, supports this hypothesis. Recruitment success in this species depends on timing of reproduction and larval release to coincide with seasonal physical forcing events. Comparing growth rates of females maturing early with seasonal timing requirements further supports the hypothesis of phenotypic plasticity of brachyuran reproduction.

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Aquatic Sciences Meeting, Albuquerque 2001

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