Influence of fertilization on ovogenesis in Ancylostoma caninum

Fertilization is necessary in Ancylostoma caninum for the formation of the inner layers of the egg shell. These inner layers appear to be formed after telophase I by coalescence of secretory granules that rise to the surface of the ovum from within. Eggs that lack these layers are very fragile and easily destroyed. The ovarian end of the uterus contains many small particles. These particles seem to coalesce around the surface of the eggs after completion of telophase I. The rate of egg laying appeared to be similar for fertilized and unfertilized females. Both unfertilized and fertilized worms laid eggs in vitro and their uteri contained similar numbers of eggs. Meiosis stopped at telophase I in unfertilized eggs and was followed by degeneration of the chromosomes. The diploid chromosome number in A. caninum is 2N = 12.