Journal of Comparative Physiology A

, Volume 181, Issue 5, pp 461–468

Orientation during short-range feeding in the crab Dotilla wichmanni

  • P. Luschi
  • C. Del Seppia
  • E. Crosio
ORIGINAL PAPER

DOI: 10.1007/s003590050129

Cite this article as:
Luschi, P., Seppia, C. & Crosio, E. J Comp Physiol A (1997) 181: 461. doi:10.1007/s003590050129

Abstract

The ocypodid crab Dotilla wichmanni is a common inhabitant of tropical sandy shores, where it feeds at low tide by sorting the material deposited by the ebbing tide. Feeding occurs in the immediate vicinity of the burrow by means of systematically sampling the sand surface. While feeding, the crabs move along trenches radiating from the burrow and produce pseudofaecal pellets which are amassed over the already excavated area. When disturbed, the crabs rapidly vanish into the burrow, where they remain hidden for a while. Upon re-emerging, they recommence feeding moving along the same trench as before retreat. The crabs, however, were found to assume the same feeding direction held before retreating even if any sign that could be derived from their previous activity was removed experimentally. To uncover the orientation cues used in this behaviour, the area near the burrow was manipulated in particular ways. The crabs were found to rely mainly on the skylight polarization pattern, while visual landmarks near the feeding area may play a role when astronomic cues provide no useful information, such as under overcast skies. Both cues were used by the crabs as references to assume the same feeding direction as that used before retreat.

Key words OcypodidaeFeeding behaviourOrientationLandmarksPolarized light

Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • P. Luschi
    • 1
  • C. Del Seppia
    • 1
  • E. Crosio
    • 2
  1. 1.Dipartimento di Etologia, Ecologia ed Evoluzione, University of Pisa, Via A. Volta 6, I-56126 Pisa, Italy, Tel.: +39-50 20447; Fax: +39-50 24653 e-mail: papi@discau.unipi.itIT
  2. 2.Centro di Studio per la Faunistica ed Ecologia Tropicali del CNR, Via Romana 17, I-50125 Florence, ItalyIT