Playa lakes are temporary water bodies that experience periods of complete desiccation and are often characterized by quick successions of communities after filling events. Triops (Crustacea: Notostraca) often dominate early successions and play an important role in shaping the community structure. This is illustrated by their predatory behavior and their habitat-shaping bioturbation behavior that agitates sediment. The physiologies and population dynamics of Triops vary greatly through the course of each hydroperiod and may be influenced by competitive and environmental pressures within the ephemeral pond community. In our study, we examined what drives Triops diet shifts to predation, how Triops shape the invertebrate community, and how the invertebrate community feeds back to impact Triops populations. We used laboratory microcosms to sample invertebrate communities emerging from soil collected from several dry ephemeral ponds. The size, fecundity, number of eggs, and body condition of Triops were measured at the end of the two-week hydroperiod. Our results indicate that Triops size as well as egg production has the potential to increase with higher temperatures and longer daylengths. Triops we did not grow as large in microcosms with high Triops densities or high fairy shrimp densities early in the hydroperiod. Our study aims to untangle factors that influence Triops populations and their communities to better understand their role in ephemeral pond community structure.
