Talk about the first generation of red algae

The male and female gametophytes are isomorphic haploid generations and bear the gametangia. The male gametangia called spermatangia produce non motile sperm cells called spermatia. The female gametangia are called carpogonia. Each carpogonium consists of a single large cell and has a long tubular hair-like extension the trichogyne that basically acts as a receptor of drifting spermatia. Since reproductive organs of Rhodophyta are non-motile, the spermatia are carried to the trichogyne of carpogonium by water currents. If a spermatium should brush against a trichogyne, it may become attached, and plasmogamy occurs. Then the nucleus of the spermatium migrates to the egg nucleus and fuses with it, forming a zygote. This type of fertilization is trichogamy. The produced zygote goes on to develop parasitically on the female gametophyte.