SCHAPKER, Heidi; BREITHAUPT, Thomas; SHURANOVA, Zhanna; BURMISTROV, Yuri; COOPER, Robin L.: Heart and Ventilatory Measures In Crayfish During Environmental Disturbances & Social Interactions

Most animals assess the environment in which they live and alter their behavior according to various stimuli. As an observer, one looks for changes in the behavior of the animal which indicates if an animal is responsive to an event. When the animal does not make significant behavioral changes, as measured by bodily movements, the animal may be characterized as unresponsive to a given stimulus. This study demonstrates that when behavioral movements of crayfish cannot be observed, physiological measures of heart rate (HR) and ventilatory rate (VR) show dramatic changes following presentation of a defined sensory stimuli. In the majority of cases, upon anticipating a social interaction with another crayfish both HR and VR will increase. During an agonistic encounter between two crayfish, the level of HR and VR correlate with the intensity of the interaction. Such rapid responses in cardiac and respiratory systems to environmental disturbances and anticipation of a social interaction suggest an autonomic-like regulation commonly associated with mammals. Since behavioral observations do not allow an internal status to be assessed, it is suggested that HR and VR may serve as useful bioindices in crustaceans to their internal drive or possibly an awareness level to environmental cues.