Skyler Carrell

    In May of 2015 I embarkered on a journey with 12 other students to the Peruvian Amazon rainforest. Each went to perform our own unique project. The project I carried out was studying studying social spiders. Here is a more in depth abstract of my work

 

    Studying the Relationship between Social Patterning and Relatedness in Anelosimus eximius

Unlike most spiders, Anelosimus eximius from the Amazonian rainforest of Peru is a social, communally living, species. Groups of A. eximius appear to coordinate their foraging/hunting behaviors much like a pack of wolves or lions. They sleep together, hunt together, and thrive together. In turn, due to the large numbers of individuals in a single colony, and apparently low emigration rates, there is a high rate of inbreeding and therefore a high relatedness quotient within individual colonies. With this in mind, we hypothesized that relatedness will be inversely proportional to distance between colonies and that spiders would prefer to be closer to conspecifics from the same colony while avoiding those from different colonies, regardless of the distance between the colonies as well as the relatedness. In the experiment described here, we captured individuals from multiple colonies and placed them in closed containers for 36 hours, taking images and recording behavior at 3 hour intervals. Images gathered in this way were analyzed based on distance between individuals and general activity patterns.  Genetic patterns from each spider colony were then tested to determine general relatedness of the spiders within and between colonies. Unexpectedly, we found that colony of origin had no impact on social behavior. We discuss this finding in light of relatedness and presumptive evolutionary factors.