When Caenorhabditis elegans (Nematoda: Rhabditidae) bumps into a bead

Abstract

When C. elegans bumps into a bead, it stops moving, withdraws a short distance, and then resumes forward movement, often in a new direction. This series of events has been analysed in its constituent parts and the features making up the 'stimulus' have been compared numerically with those making up the 'response.' No significant correlations were found that support the interpretation that this is a simple stimulus–response phenomenon. It is argued that the data support an alternative view that when forward movement is interrupted, C. elegans is primed to undergo a short, rapid reversal and that this is not mediated through sensory mechanoreceptors.