Punctured Planarians and Alarm Cues for Conspecifics

Abstract

Abstract: We attempted to answer whether or not planarians signal to conspecifics with the use of chemical alarm cues. To mimic predation, planarians were punctured 10 times with a pin and allowed to settle while the supposed alarm cue was released. The solution around the planarians was extracted and used as a test solution. Planarians were placed into straws that had been cut in half with test and control solutions at either end. This forced the planarians to decide between the two solutions. The results proved inconclusive as to the preference of the test solution over the control solution. In contrast, solutions prepared by grinding up planarians elicited avoidance, as previously shown by Wisenden and Millard (2001). These results provide a possible foundation to the hypothesis that the planarian’s avoidance of the ground-up planarian solutions is due to the presence of high concentrations of noxious chemicals rather than a true alarm cue.