The sensory, microbiological and biochemical changes were determined in shrimp (Penaeus merguiensis) stored at 0° to 35°C. Mean aerobic plate count of fresh shrimp, initially 5.0 × 105 CFU/g, increased with time and temperature to 6.4 × 109 CFU/g at 35°C after 24 hr. A total of 560 different bacteria were isolated and identified. In addition, the dominant organisms were tested for ability to reduce TMAO, produce indole and hydrolyze protein. The initial bacteria were 30% Gram + organisms but changed to predominantly Grampsychrotrophs at lower temperatures and to mesophiles at higher temperatures. Odor, texture and color qualities decreased; TMA, TVB, pH and Indole increased with time and temperature. Shelf life of shrimp ranged from 7 hr at 35°C to 13 days at 0°C.