Journal of Comparative Physiology A

, Volume 192, Issue 3, pp 321–331

Physiological characterization of the compound eye in monarch butterflies with focus on the dorsal rim area

Authors

    • VW Nachwuchsgruppe Animal Navigation, IBUUniversity of Oldenburg
  • Thomas Labhart
    • Zoological InstituteUniversity of Zürich
  • Henrik Mouritsen
    • VW Nachwuchsgruppe Animal Navigation, IBUUniversity of Oldenburg
Original Paper

DOI: 10.1007/s00359-005-0073-6

Cite this article as:
Stalleicken, J., Labhart, T. & Mouritsen, H. J Comp Physiol A (2006) 192: 321. doi:10.1007/s00359-005-0073-6

Abstract

The spectral, angular and polarization sensitivities of photoreceptors in the compound eye of the monarch butterfly (Danaus plexippus) are examined using electrophysiological methods. Intracellular recordings reveal a spectrally homogenous population of UV receptors with optical axes directed upwards and ≥10° to the contralateral side. Based on optical considerations and on the opsin expression pattern (Sauman et al. 2005), we conclude that these UV receptors belong to the anatomically specialized dorsal rim area (DRA) of the eye. Photoreceptors in the main retina with optical axes <10° contralateral or ipsilateral have maximal sensitivities in the UV (λmax≤340 nm), the blue (λmax=435 nm) or in the long-wave range (green, λmax=540 nm). The polarization sensitivity (PS) of the UV receptors in the DRA is much higher (PS=9.4) than in the UV cells (PS=2.9) or green cells (PS=2.8) of the main retina. The physiological properties of the photoreceptors in the DRA and in the main retina fit closely with the anatomy and the opsin expression patterns described in these eye regions. The data are discussed in the light of present knowledge about polarized skylight navigation in Lepidopterans.

Keywords

Danaus plexippusCompound eyeDorsal rim areaPolarization sensitivitySpectral sensitivity

Abbreviations

DA

Dorsal area

DRA

Dorsal rim area

ERG

Electroretinogram

PS

Polarization sensitivity

Copyright information

© Springer-Verlag 2005