Caulerpa longifolia

Caulerpa longifolia, commonly known as feather caulerpa or long-filament caulerpa, is a species of seaweed in the Caulerpaceae family.
The seaweed has a coarse stolon with medium to dark green fronds reaching in height and wide. It has few upright branches that arise from a naked and coarse runner. The ends of the branches are linear or curved slightly upwards, usually occurring in five rows along the upright branches. It has a superficial similarity to Caulerpa cliftonii.
The species is found in rough coastal waters around rock pools to a depth of. In Western Australia, it is found along the coast from Shire of Irwin in the Mid [West |Mid West] and south as far as Rockingham, [Western Australia|Rockingham] it is also found in South Australia, Victoria and Tasmania.