Amy Bruestle A Comparative Survey of Chemosensor Structure and Arrangement on Crayfish Antennules: Does Flow Environment Predict Structure? Division Sciences Department Biology Year 2003 Advisor Kristina Mead

Crayfish flick their antennules in order to sample their olfactory environment.  This action distributes chemical information to chemoreceptive aesthetascs on the outer filament of the antennule.  Because flow environment affects the structure of odor plumes, I hypothesized that species from different flow environments would have different numbers and arrangements of chemosensors along their antennule filaments.  I hypothesized that those structures might vary as a function of position along the antennule filament.  This study utilizes both light and scanning electron microscopy to measure a variety of parameters that describe aesthetasc arrangement and structure in seven species of crayfish. I found that some parameters (aesthetasc size and arrangement) varied as a function of flow environment, and that some parameters (aesthetasc distribution and arrangement) varied as a function of position.