Development of Notophthalmus viridescens embryos.

Although the North American, adult, red-spotted newt has been an excellent model in the study of appendage regeneration at the tissue and cell levels, experiments involving embryonic forms have been essentially impossible to perform at the molecular level due to the great difficulty in breeding newts in the laboratory. Recently, we reported our methods to successfully spawn many thousands of embryos of Notophthalmus viridescens for developmental studies on a year round basis. As no detailed examination of embryogenesis of this amphibian exists, we provide a scanning electron microscopic overview of N. viridescens development. Furthermore, we chronicle the life cycle of the newt, when produced under laboratory conditions, which also undergoes two metamorphoses as newts in the wild.