The catarina scallop Argopecten ventricosus,is among the shortest-lived scallop species. It reaches market size within a year and is of high commercial value, (Maeda-Martínez et al. 2000). Due to its very short lifespan of only 2-3 y, this scallop is an ideal model to study how internal and environmentally factors modulate growth and aging. In our study we are testing the effect of one abiotic physical factor: elevated temperature and of the biotic stressor predation on growth and physiological aging of the catarina clam of the pacific coast of Baja California Sur, Mexico. Animals were obtained from a hatchery (genetically similar animals) and grown in the laboratory for 1 œ Months to a size of 5 mm until the young animals were exposed to different experimental conditions in the laboratory and in the field. One part of the animals is being raised in the laboratory under different temperature regimes: in situ field temperatures and in situ field temperatures but elevated max. 5°C. Another part of the animals is reared directly in the field inside the sea grass as well as nestier trays (predator protected area) and outside sea grass (predator exposed area). The growth, metabolic rate and biochemical parameters are being analyzed in all different experimental groups over a time frame of two years to evaluate the physiological adaptations to the different environments conditions and experimental stressors. Scallops in the field grew more rapidly than animals maintained in the laboratory. The mean growth was 0.5 mm/day for the laboratory animals, compared to 2.3 mm/day for field animals. Animals grown at 5°C higher temperature in the Lab grew 4% slower than animals at in situ temperatures. Currently the measurements of metabolic rate and of scope of growth are carried out to determine the energetic balance and expenditure in the different treatments. Tissue antioxidant capacities and the activity of antioxidant enzymes are being measured. First results of the field animals before and after release to different environments, and the laboratory animals exposed to two different temperatures will be shown in the Symposium in September.