Meeting Abstract
Storage of fat and its subsequent mobilization in organisms often fuels important energetically-costly life-history functions. This is particularly true when individuals are unable to feed during the periods when energy is needed, such as mating and pregnancy. The extent of fat deposition may vary among populations depending on prey size, as this trait is an important determinant of the amount of energy available for storage. Additionally, males and females should differ in the timing and extent of fat deposition/mobilization as their energetic demands differ. To examine the effect of prey size and sex on fat deposition/mobilization we examined four populations of the diamond-backed watersnake (Nerodia rhombifer) at fish farms with variable fish sizes. Individuals from each population (8-10 of each sex) were sacrificed monthly over the course of two fields seasons (2013 and 2014). We measured the wet mass of fat bodies, liver, and gonads and compared seasonal differences in length-corrected weights among populations and sexes. Patterns of weight changes in these tissues corresponded with important annual life-history stages and appear to vary among populations and sexes. We suggest that these differences correlate with variation seen in other life-history traits among these populations.
