From: itannman@dogbert.ucdavis.edu (Ann Mansker)
Subject: Critter of the Week: Basiliscus basiliscus
Date: 21 Nov 1997 00:00:00 GMT
Newsgroups: ucd.life


The basilisk lizard is native to Central and northern South America.  The
sexes are easily distinguished, as the male has a prominent crest, which is
clearly visible in this image:

http://reality.sgi.com/davis_asd/costarica/malebasilisk.jpg

This rather large (2ft) lizard is both an agile climber and a strong 
swimmer.  It is known locally as "Jesus Christo" due to its habit of
running bipedally across water to escape enemies.  Juveniles are able to
drop from an overhanging branch into water, swim to the surface and run off.
As the lizard grows, it eventually reaches a point where it can no longer
generate enough downward force to run more than a few steps.  The basilisk's
foot is not webbed; the toes have a fringe of scales that spread out as the
foot is slapped down, and fold in as the foot is withdrawn from the water.
An important factor in the lizard's water-running ability is the air pocket
that forms as the foot strokes into the water.  This pocket supports the
lizard at the surface; a critical part of the water-running technique is
slipping the foot out of the pocket before the bubble collapses.  An article
describing the mechanism was published in the Journal of Experimental
Biology: 

http://www.cob.org.uk/JEB/199/12/jeb0284.html