Integrating development and environment to model reproductive performance in natural populations of an intertidal gastropod

Functional challenges can differ among life-history stages,yet performance at one stage may be linked to the outcome ofperformance at others. For example, adult performance, in termsof the location or timing of reproduction in response to environmentalsignals, can set conditions that affect the performance of developmentalstages. In marine invertebrates, however, early performancehas been studied primarily in the laboratory. I outline an integrativeapproach to the study of field reproductive performance in amarine gastropod that undergoes development in intertidal habitats.Embryos within gelatinous masses experience high variabilityin development temperature and frequent exposure to thermalstress. In laboratory experiments, developmental performancewas measured as a function of maximum temperature (T_max) experiencedduring fluctuations that mimicked field tidal profiles. Performancecurves showed declines that coincided with temperature thresholdsfor heat shock protein (Hsp) expression, a signal of cellularstress. Application of laboratory results to field records ofT_max predicted large variation in the survival of embryos depositedon different days. Timing of field reproduction was non-randomwith respect to T_max, suggesting that adults could help to bufferembryos from environmental stress. Embryo survival, however,was not predicted to benefit from the non-random pattern ofadult reproduction. Adults may be constrained to respond toinformation that only weakly predicts conditions that embryoswill experience. Studies that incorporate linkages between lifecycle stages in the field may better reveal how performancecapacities and constraints at one stage can influence performanceand selection at others.