This thesis paper is about the observation of changes in the survival of Hydra upon immune challenge by lipopolysaccharide or LPS. LPS is a substance that challenges the hydra's immune system and therefore was used on 3 male strains and 3 female strains of hydra to see the changes. The study was based on two hypotheses. The first one was that if Hydra were infected with bacteria, they would sense an increased risk of mortality and make a life history decision that would lead to increased reproduction or reproductive investment. The second hypothesis was that fighting off the bacterial infection would be costly and would draw out energy saved for reproduction and/or survival, therefore resulting in a decrease in reproduction. The study did not find any significant differences between the treated and control groups for any of the six strains of Hydra, indicating that the treatment did not have a significant effect on survival time.