The impact of refrigeration on research cadavers during the bloat stage of decay and the potential entomologic and taphonomic implications

Research cadavers are refrigerated for varying lengths of time; this artificial factor, inherent to cadaver research, may affect entomologic and taphonomic studies. Refrigeration can alter the bacterial composition, potentially leading to changes in volatile emissions that may affect insect recruitment and the rate of decomposition. Cats were used as an analog to humans for preliminary exploration of these artificial factors. Twenty-one cats were split into seven sets of three with each set containing frozen, refrigerated and freshly euthanized cats. Variation in the bloat stage of decay measured via maximum abdominal distention was used to explore if outward taphonomic features are changed by previous amounts of cooling. Additionally, cooling during decomposition can cause transitions between the stages of decomposition to be imprecise where the cadaver can possess features from two stages concurrently. After being found dead, a man was refrigerated for approximately two months then placed outdoors in Southeast Texas for entomologic and taphonomic studies. When received, the cadaver had dead, third instar Chrysomya ruffifaces (Macquart, 1842) larvae present, darkened and slipping skin and no notable abdominal distention. Based on this information, it was assumed that he had bloated at his apartment. By 24 August 2009 the cadaver had become fully bloated at the research facility. To our knowledge the literature has not documented the abdomen swelling twice during the bloat stage. By both limiting insect activity during early decomposition and cooling during the bloat stage we were able to experimentally recreate abdominal swelling twice in eight cats.