The feeding ecology of small, benthic aquatic invertebrates is notoriously difficult to study. Many of these organisms are crustaceans, a clade that is known to contain many omnivorous, opportunistic foragers. We hypothesize that the microflora of gastrointestinal tracts will provide insights into the diets of these difficult to study organisms. Specifically, this project will compare the microflora in the gastrointestinal tracts of Hyalella sp. amphipods grown in different resource environments. The identification of microorganisms will be performed by isolating the genomic DNA from the contents of amphipods' gastrointestinal tracts followed by polymerase chain reaction amplification of the bacterial 16S rRNA regions. Once amplified, the DNA fragments will be subjected to sequencing. The bioinformatic analysis will be used to identify the abundance of microbial species that make up the Hyalella sp microflora. Our results will provide valuable information on the power of this approach to explore the feeding ecology of benthic, aquatic invertebrates.