MARTIN, Arthur/L; BERGMAN, Daniel/A; MOORE, Paul/A; Bowling Green State University; Bowling Green State University; Bowling Green State University: Social communication in crayfish: a simultaeous recording of urine signals and flow fields during agonistic encounters
Many animals use sensory information when making decisions regarding social status. Crayfish use chemical signals to determine the past social history and status of conspecifics. These signals likely originate in the urine that is actively released during agonistic encounters. The transfer of social information is further facilitated during these encounters by the generation of currents that carry urine to opponents, which in turn respond to the signaling conspecific. Small, neutrally buoyant particles, along with a projected light sheet were used to quantify the role of these information currents during agonistic bouts. Both dominant and subordinate crayfish generate these currents and use them to send and sample signals; however, differences exist where dominant crayfish generate more pleopod currents and exhibit more antennal whips. Information current alterations correlated with behavioral modifications, suggests that currents are used to transfer information, which can alter subsequent agonistic acts. Information within these flow fields are likely present with in the urine, thus a fluorescent dye was used to correlate urine release with agonistic behaviors. Results indicate that dominant animals release urine during an encounter more often than subordinates do, and do so while engaged with an opponent. Finally, a unique combination of the two aforementioned techniques confirmed that urine is in fact transported by crayfish generated currents. The correlation of urine release to flow field generation appears to be an indicator or may be the result of eventual dominant- subordinate relationships. Consequently, Orconectes rusticus may use chemical signals to alter or possibly control the receiver�s behavior during the course of an agonistic interaction.
