Posted by seahunt on January 06, 2003 at 08:31:43:
My friend sent me this link about lobster navigation.
www.unc.edu/depts/oceanweb/lobsters/
It's amazing what they can do. The story is:
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Orientation, Homing, and Navigation in Spiny Lobsters
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.
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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.