Zachary Zollman Rose Hills
Desiccation resistance across Californian Tetragnatha populations
As anthropogenic climate change progresses, there is an increasing need to understand how organisms tolerate hot, arid conditions without desiccating, or drying up. In many arthropods, aridity tolerance is impacted by the outer covering of their bodies, the cuticle, especially its waxy outer layer, the epicuticle. This layer can help retain moisture by reducing evaporation rates. The chemical composition of the cuticle may impact moisture retention, and thus the ability of arthropods to persist under global heating. We plan to analyze specimens of two spider species (Tetragnatha versicolor and T. laboriosa) from populations in various regions of California. Both species are distributed throughout the state near bodies of water, though they have different habitat preferences, with T. laboriosa typically found in drier environments. We will evaluate how quantities, lengths, and double bond counts of methyl-branched cuticular hydrocarbons vary across populations, which may allow inference on the role of specific compounds that promote aridity tolerance. We hope that our findings will refine conceptual understanding and statistical modeling of how organisms can adapt to altered moisture conditions.