Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 15, 2013 | Published
Journal Article Open

Discontinuous locomotion and prey sensing in the leech


The medicinal leech, Hirudo verbana, is an aquatic predator that utilizes water waves to locate its prey. However, to reach their prey, the leeches must move within the same water that they are using to sense prey. This requires that they either move ballistically towards a pre-determined prey location or that they account for their self-movement and continually track prey. We found that leeches do not localize prey ballistically. Instead, they require continual sensory information to track their prey. Indeed, in the event that the prey moves, leeches will approach the prey's new location. While leeches need to continually sense water disturbances to update their percept of prey location, their own behavior is discontinuous – approaching prey involves switching between swimming, crawling and non-locomoting. Each of these behaviors may allow for different sensory capabilities and may require different sensory filters. Here, we examined the sensory capabilities of leeches during each of these behaviors. We found that while one could expect the non-locomoting phases to direct subsequent behaviors, crawling phases were more effective than non-locomotor phases for providing direction. During crawling bouts, leeches adjusted their heading so as to become more directed towards the stimulus. This was not observed during swimming. Furthermore, in the presence of prey-like stimuli, leeches crawled more often and for longer periods of time.

Additional Information

© 2013 Published by The Company of Biologists Ltd. Received 12 June 2012; Accepted 23 January 2013. The authors thank Karen Mesce for her valuable input on the discussion of this manuscript, as well as two anonymous reviewers, whose comments aided in improving the manuscript. Author Contributions: C.M.H and D.A.W. designed the experiments. C.M.H, J.C. and M.R. performed data analysis and experiment execution. C.M.H. wrote the manuscript. D.A.W. and C.M.H. edited the manuscript. Funding: Funding for this study was provided by the Burroughs Wellcome Fund and the Broad Foundations (to D.A.W).

Attached Files

Published - 1890.full.pdf


Files (798.5 kB)
Name Size Download all
798.5 kB Preview Download

Additional details

August 19, 2023
October 23, 2023