and life history of
Silvetia (which was called Pelvetia)
The life history of S. compressa is interesting in that it lacks a sporophyte stage. The thallus is diploid and it produces haploid gametes in conceptacles located in receptacles at the tips of ultimate dichotomies. Once released, these gametes fuse and form a zygote which grows into another gametophyte. Silvetia, therefore, has a life cycle very similar to the human cycle.
One very interesting feature of S. compressa is the increase in cellular activity when making sections of the receptacles. After sectioning a receptacle, the oogonia undergo divisions and are released from the conceptacles out the ostia.
S. compressa would be a useful tool for science teachers who wish show students examples of cellular activity.
© 1996 R. H. Lin