The Caribbean spiny lobster, Panulirus argus, is an active, migratory crustacean commonly found in coral reef ecosystems of the western Atlantic. For most of the year, spiny lobsters spend daylight hours inside coral reef crevices, emerging at night to forage over considerable areas before returning in nearly total darkness to the same den or to one of several others nearby. Lobsters are also capable of homing to a specific den if displaced to an unfamiliar area. The ability to maintain consistent headings while migrating under water, and to move reliably even in darkness to specific targets such as dens, imply that lobsters possess a remarkable suite of orientation and navigation mechanisms.
The complexity and sophistication of lobster guidance systems has only recently become apparent. New studies have revealed several surprising findings. The first is that lobsters have a well-developed magnetic compass sense that enables them to establish and maintain courses relative to the Earth's magnetic field. Even more surprisingly, lobsters can derive positional information from the Earth's magnetic field and use this to help them figure out their geographic location. This remarkable ability, known as a "magnetic map sense", endows the lobsters with a sensitive navigational system rivaling that of sea turtles and homing pigeons. In this series of web pages, we summarize what is known about spiny lobster orientation, homing, and navigation.
These web pages are based on the following two published papers:
Lohmann, K. J., Pentcheff, N. D., Nevitt, G. A., Stetten, G., Zimmer-Faust, R. K., Jarrard, H. E., and L. C. Boles. 1995. Magnetic orientation of spiny lobsters in the ocean: experiments with undersea coil systems. Journal of Experimental Biology. 198: 2041-2048. Download this paper in Adobe PDF format.
Boles, L. C. and K. J. Lohmann. 2003. True navigation and magnetic maps in spiny lobsters. Nature. 421: 60-63. Download this paper in Adobe PDF format. (Note: may require institutional subscription to Nature.)
photo from The Vibrant Sea