Meeting Abstract
Many different aquatic species exhibit changes in behavior when exposed to hypoxic waters. Crayfish are a highly diverse species that are found in a variety of waters both hypoxic and normoxic. Crayfish experience adverse physiological effects in hypoxic waters, but it is unknown if crayfish exhibit a preference to areas with higher oxygen concentrations. The purpose of this study was to analyze the responses of the crayfish, Orconectes rusticus, when exposed to varying levels of oxygen. Each animal was placed in a y-maze (working section: 30.5 x 61 x 30.5cm, arms: 30.5 x 43 x 30.5cm) with each arm containing water of different oxygen concentrations, ranging from 1 to 6 mg O2/l. A current of 10 cm/sec was streamed through each arm of the y-maze. After each set of initial trials, data was analyzed based on initial arm choice, time spent in each arm, and time spent at the furthest upstream position. When the results showed significant preference, a new scenario was designed with a narrower margin of difference between oxygen levels. In contrast, when results illustrated no preference, the crayfish were presented with a wider margin of difference, for subsequent trials. This allowed us to determine if Orconectes rusticus exhibits an oxygen preference, thus demonstrating its potential habitat selection based on a range of oxygen levels.
