Talk about trichogamy

Trichogamy is a mode of fertilization that occurs when a male, non-motile spermatium (carried by water currents) collides with a hair-like extension of the female gametangia, the trichogyne. The spermatium and the trichogyne fuse their cytoplasms then the nucleus of the spermatium migrates through the trichogyne and fuse with the egg nucleus. e.g. Red algae