The
nematode worm (
Caenorhabditis elegans) is a very small worm, verging on the
microscopic (~0.1
mm in length).
Developmental biologists (among other
biologists) love it because all
adults have the same
number of
cells (
94), and it develops in a simple fixed order. It also has a very simple
nerve system, which is fully understood.
In December 1998, C. elegans became the first multicellular organism to have its genome completely sequenced (by the UK's Sanger Centre); see: C. elegans: Sequence to Biology, Science Dec 11 1998 (entire issue).