Host tracking and photosensitivity in Chaetogaster limnaei limnaei (Oligochaeta)

Abstract

Chaetogaster limnaei limnaei were separated from host snails (Physa skinneri) for increasing periods of time. The oligochaetes responded to a snail's slime trail by increased activity and distance moved along the slime trail. These responses increased with increasing periods of separation from the snail. When exposed to a directional light source, C. l. limnaei displayed an initial positive phototactic response. Movement towards light from the same direction decreased significantly in a second 4-h period, but movement towards light from a different direction was equivalent to the initial response, suggesting the response was an initial one to a change in light.