If students are working individually or in groups, appropriate precautions should be taken when using single-edged razor blades. No special problems are presented with the use C. elegans or the medium in which it is cultured. Males tend to be slender and more active than hermaphrodites, and have tails with fan-shaped rays. All normal hermphrodites contain exactly 959 cells and males contain 1047. The fate of all cells has been determined and studied.
Hermaphrodites carry out self-fertilization, or, preferentially, are fertilized by males.
Over 300 eggs are produced by a single hermaphrodite, and embryogenesis and may be viewed in various stages while still in the body cavity of the parent. The fertilized egg undergoes the first cleavage within 40 minutes, in which the anterior and posterior regions are formed. Successive cell divisions may occur at intervals of 15 minutes or less. Transparent bodies and eggs allow structures to be easily seen when viewed with a light microscope under high power. Worms are available on a culture dish of medium with a lawn of E. coli , the primary food for the nematode.