Wild type C-Fern sperm, when released from the antheridium, are encased in a thin-walled vesicle. Several seconds after release, the sperm break free of the vesicle and quickly swim away. In contrast, most zzz1 sperm remain in the vesicles after release and some eventually break free only after several minutes. The free sperm typically move only slightly or swim very slowly to moderately, with some showing faster movement. The more normal types apparently allow zzz1 gametophytes to self fertilize, despite the abnormalities in most zzz1 sperm. This EMS-generated mutant is excellent for observations at both low and high ( greater than 50X) magnifications.

Duckett, J.G., E. J. Klekowski and L. G. Hickok. 1979. Ultrastructural studies of mutant spermatozoids in ferns. I. The mature nonmotile spermatozoid of mutation 230X in Ceratopteris thalictroides (L.) Brongn. Gamete Res. 2:317-343.