Marine Biology

, Volume 119, Issue 3, pp 347–356

Sun-compass migration by Aurelia aurita (Scyphozoa): population retention and reproduction in Saanich Inlet, British Columbia


  • W. M. Hamner
    • Department of BiologyUniversity of California
  • P. P. Hamner
    • Department of BiologyUniversity of California
  • S. W. Strand
    • Department of BiologyUniversity of California

DOI: 10.1007/BF00347531

Cite this article as:
Hamner, W.M., Hamner, P.P. & Strand, S.W. Marine Bioliogy (1994) 119: 347. doi:10.1007/BF00347531


The scyphomedusa Aurelia aurita in Saanich Inlet, a north-south oriented fjord in British Columbia, uses a sun compass to migrate in a southeasterly direction during the day. When the sky is overcast and at night, A. aurita orients randomly and is dispersed passively by gentle tidal currents. The net result is daily reaggregation of medusae into enormous swarms along the southeastern shore of the fjord. Observations of spawning A. aurita in these swarms suggest that sun-compass migration and aggregative behavior may have evolved to facilitate reproduction and to maintain the population within this fjord throughout the year.

Copyright information

© Springer-Verlag 1994