Abstract

Hagfishes have long held a key place in discussions of early vertebrate evolution. Frustratingly, one basis for such discussions—namely hagfish embryology—is very incompletely known, because the embryos of these animals are notoriously difficult to obtain.1,2 Fortunately, a recent publication on a Far Eastern hagfish3 describes a workable procedure for obtaining embryos and then uses this precious material to show that the hagfish neural crest arises by cell delamination as in other vertebrates—and not by epithelial outpouchings from the wall of the neural tube as previously claimed.4 Importantly, because hagfish embryos should now be available on a regular basis, the way is open for additional morphological and developmental genetic investigations to help evaluate existing evolutionary scenarios and perhaps suggest new ones. BioEssays 29:833–836, 2007. © 2007 Wiley Periodicals, Inc.