Thesis (M.S., Natural Resources) -- University of Idaho, 2015 | Growth, hatching, and anti-predator defenses were studied in Lepidurus lemmoni from several lakes throughout its range. Growth of L. lemmoni was well described by a sigmoidal curve, with growth slowing after sexual maturity. Carapace sexual dimorphism of L. lemmoni developed well before sexual maturity and differed significantly between females, males, and immatures. Average hatching day was inversely correlated with temperature, and not affected by salinity. Cumulative egg hatch was inversely related to temperature in Goose Lake and Middle Alkali Lake, but peaked at 13.5°C in Dowling Lake L. lemmoni. Cumulative hatch was uniformly lowest across all temperatures at 0.0ppt, significantly so in Goose Lake L. lemmoni. Middle Alkali Lake L. lemmoni had significantly higher egg mortality than L. lemmoni from Goose or Dowling lakes. Defensive morphology was induced by temperature, and non-lethal injury to a limited extent, but not alarm cues or kairomones.