Bryopsis has a two phase life cycle that alternates between the familiar, macroscopic gametophyte and an inconspicuous, microscopic sporophyte. This cycle is distinct from many other green algae, such as Ulva, whose gametophyte and sporophyte look identical. The gametophyte of Bryopsis is coenocytic, but the gametes, spores, and sporophyte are uni-nuclear. The gametes are biflagellated. In addition to reproduction from gametes and spores, Bryopsis is also capable of reproduction from algal fragments or extruded protoplasm that lacks a cell wall. When the multinucleated cells of Bryopsis are injured, the protoplasm that is extruded from the cells can generate new cells. The coencyte's cell organelles aggregate and secrete a gelatinous envelope and then a cell wall around themselves. Hundreds of cells can be generated from a broken branch, many of which can develop into new plants.
Bushy Green Algae Bryopsis plumosa
A Single Plume of Bryopsis plumosa
The life cycle of Bryopsis involves the alternation of two heterothallic stages: the familiar, macroscopic gametophyte and the inconspiruous, microscopic sporophyte. Bryopsis can also reproduce by fragmentation of microthalli.
Coenocytic nuclei in the growing tip of Vaucheria terrestris sensu Goetz, another coenocytic alga. a) photomicrograph of a growing tip and b) nuclei in the same region stained with a blue dye.