WILBORN, S.E.; MOORE, P.A.: The effect of boundary layers on chemical signals perception in blue crabs

When looking at sensory signals, specifically olfactory signals, we must realize that a signal is sent through an environment and then received by a receptor organ. The signal passes through a boundary layer, which surrounds the receptor organ. So to investigate how the boundary layer alters the signal structure as it approaches the organism, we created a model of a blue crab (Callinectes sapidus) to use in our experiments. The model was placed in a recirculating flume with a microelectrode touching its antennules. The microelectrode detects a tracer chemical, dopamine. The flow speed was set at 0.05 m/s and the dopamine was released into the flume upstream from the model for three minutes. Trials were run with and without the antennules and the body was positioned at different angles, 0 degrees, 45 degrees, and 90 degrees in relation to upstream. The presence of both the antennules and the angle relative to upstream influences signal structure. These results have implications for how blue crabs perceive odor signals during orientation behavior.