Embryonic development of the freshwater crayfish (Pacifastacus leniusculus Dana): a scanning electron microscopic study.

The egg development of the freshwater crayfish (Pacifastacus leniusculus Dana) under laboratory conditions is studied in this work from spawning to hatching. The sequence of its development is presented here, and the chronology of the different embryonic phases is established at one specific temperature (15.5 degrees +/- 1 degree C).