Polarized light sensitivity in the zoea of the rock crab (Panopeus herbstii)

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Mark Bardolph (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Robert Stavn

Abstract: This study was undertaken to investigate polarotaxis (orientation to the e-vector of polarized light) in the zoeae of the xanthid crab, Panopeus herbstii. Several lines of behavioral evidence indicate that arthropods are able to perceive polarized light as a stimulus distinct from light pattern (image) perception. The optical environment in this study was made as natural as possible to allow more realistic extrapolations from orientational behavior to the ecological relations of this group. Panopeus herbstii larvae were cultured at 25° C in 25 /00 filtered sea water, and on a 12:12 hour light:dark cycle. The first and second stage zoeae were tested for their orientation in different light intensity distributions both with unpolarized light or polarized beams from the sides (the e-vector horizontal or 20° off the horizontal). This was accomplished by placing the animals in an experimental apparatus which consisted of a glass cuvette suspended within a large supporting structure on which lamps, filters, camera, and electronic flash heads were counted. Thus, the animals could be photographed while being subjected to a variety of light regimes. An enlarger was used to project the Images from the photographic negatives onto a piece of paper. The orientations of the animals' rigid dorsal spine could then be drawn, measured, and tabulated. The Mann-Whitney (Wilcoxon) U test was used for location comparisons; dispersions about the median orientation were compared using the Siegel-Tukey test.

Additional Information

Language: English
Date: 1976
Crabs $x Effect of light on
Light $x Physiological effect

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