The Devils Hole pupfish consumes a variety of food items representing nearly all possible food resources in Devils Hole. Its food resources include inorganic particulate matter; the algae "Spirogyra" and diatoms; the freshwater crustaceans "Hyalella azteca" and ostracods; protozoa; the beetle "Stenelmis calida"; the flatworm "Girardia dorotocephala"; and the freshwater snails "Tryonia". The consumption of the various food resources varies seasonally, though inorganic particulate matter had a high frequency of occurrence in stomach contents year-round in one study. The inorganic particulate matter consists of primarily travertine, a form of limestone. The three most common food items for each season by frequency of occurrence were: