A sequential hermaphrodite is a type of
hermaphrodite which starts out life as one
sex and will either turn into a member of the
opposite sex at a later point in life (this happens in some
fish species) or will be capable of doing so if an
appropriate condition arises. For example, the removal of all of the
males in an organism's
population might trigger the most
dominant female to become a
male.
From the science dictionary at http://biotech.icmb.utexas.edu/