Barnacle settlement behavior measured by EthoVision 3.0

J.-P. Maréchal and A.S. Clare

School of Marine Science & Technology, University of Newcastle, Newcastle upon Tyne, UK

Most sessile marine benthic invertebrates have a complex life cycle comprising several planktonic larval stages. As these larvae have to return to a surface to complete their life cycle, it can be argued that settlement strategies are of primary importance. The settlement stage of barnacles is the cypris larva. During settlement, the cyprid shows two main behaviors: swimming and searching. The latter involves the use of the cyprids’ ambulatory organs – the paired antennules – which it uses to ‘walk’ over the substratum testing, it for a suitable place to settle. Searching behavior can be further subdivided into:

  1. ‘Inspection’ where the cyprid may make frequent turns but there is little or no movement over the substratum.
  2. ‘Close searching’ which involves exploration of the substratum, characterized by small steps with frequent changes of direction, punctuated by the antennules testing the substratum.
  3. ‘Wide search’ during which the cyprid traverses the substratum in a comparatively straight line with few stops.

Paper presented at Measuring Behavior 2005 , 5th International Conference on Methods and Techniques in Behavioral Research, 30 August - 2 September 2005, Wageningen, The Netherlands.

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