Sea urchin life-history strategies

Abstract Life history strategies are based on the characteristics of organisms that affect their fitness. Two environmental factors important in determining the life history strategy of organisms, including sea urchins, are stress, conditions that reduce production and disturbance, partial or total destruction of biomass. Disturbance includes predation. Different characteristics of different life history strategies are associated with different combinations of levels of stress and disturbance. The hypothesis that these characteristics are associated with particular habitats was tested by predicting where sea urchins with particular life history characteristics would occur. The habitats considered (the deep sea, Antarctic waters, tropical reef flats, kelp forests and tropical seagrass beds) differ in the levels of stress and disturbance. Species with different life history characteristics were found in the predicted habitats. Recognition of the life history strategies of sea urchins species is basic to understanding their biology and ecology. Knowledge of the strategies of extant sea urchins is useful for paleobiological and paleoecological studies. Strategies have important implications for fisheries management, conservation and evaluation of species for aquaculture. Habitats may be expected to change with ocean warming and acidification. The response of sea urchin species to the predicted changes may vary with life history strategy.