The Sea Urchin Embryo: A Remarkable Classroom Tool

Abstract

The experimental material of choice for the investigation of many developmental mechanisms is the sea urchin embryo (Giudice 1986; Davidson, et al. 1982; Oppenheimer & Lefevre 1989). It is the organism of choice because of specific qualities that also make it ideal for classroom use. Unlike chick embryos, which are covered by shells and available in small numbers, and unlike frogs, whose males are often sacrificed to obtain sperm and females are hormonally induced to ovulate, sea urchin embryos are available by the billions and clearly display embryonic development. No shells are present to block viewing and all experiments are done in the simplest of media-natural or artificial sea water. And, teachers can easily obtain sea urchins. Sea urchin embryos have been used for decades in the classroom and research laboratory and are the finest tools available for introducing students to the wonders of embryonic development and the world of research science. This article will illustrate how the sea urchin has been used to uncover key developmental mechanisms and how it can be used in the classroom to excite the students' curiosity and facilitate their introduction to well defined research experiences.