Bryopsidales is an order of green algae, in the class Ulvophyceae.[
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Characteristics
The thallus is filamentous, highly branched, and may be packed into a mass. It is Coenocyte, having multi-nucleate cells consisting of cytoplasm contained within a cylindrical cell wall. There are no Septum, and the many discoid chloroplasts, nuclei and other are free to move through the organism. The whole organism may consist of a single cell; in the genus Caulerpa, this single cell may be several metres across. In the genus Halimeda, whole seabed meadows may consist of an individual, single-celled organism connected by filamentous threads running through the substrate.
Reproduction
Propagation is normally vegetative from small fragments which grow into new individuals. Under certain conditions, sexual reproduction occurs in a process called holocarpy. Almost all of the cytoplasm in the thallus is converted into biflagellate , which are discharged into the sea through papillae. After fertilisation, the zygote becomes a protonema and this, in turn, develops into a new thallus.[ Overview of the Genus Caulerpa Proceedings of the International Caulerpa taxifolia Conference, 2002.]
Phylogeny
Molecular phylogenetic studies suggest the following relationships between extant taxa (Chaetosiphonaceae not included):
