Ref ID : 7654
Hans-Werner Kuhlmann; Escape Response of Euplotes octocarinatus to Turbellarian Predators. Arch.Protistenkd. 144:163-171, 1994
Reprint
In File
Notes
Physical contact between the freshwater ciliate Euplotes octocarinatus and its turbellarian predator, Stenostomum sphagnetorum, elicits a behavioural response of the potential prey which is different from the normal "avoiding reaction" of Euplotes. Because of its defensive character it is called "escape response". The response was analysed by the use of a video camera and recorder system. It was found that the escape response takes a regular course, beginning with sudden backward moving of Euplotes, followed by a rapid turn around and a subsequent forward movement. Velocities during the escape response are 1 to 5 times higher than calculated for control cells. The whole reaction lasts about 2 sec. Within this time a Euplotes cell moves more than 1,000 um away from its predator. While 90% of well-fed Euplotes cells demonstrated the defensive response, starved cells cultivated separately from their predators revealed fewer escape responses, however, several of the starved cells regained the capacity for the escape response after exposure to Stenostomum or Stenostomum-conditioned medium for 20 hr. It is discussed whether or not the inducible behavioural response is triggered by the same predator-released substances that are known to induce defensive morphological changes in Euplotes.