Caulerpa Caulerpa filiformis
Caulerpa is a seaweed with a dense mass of bright green, small, strap-like leaves called ramuli. Each ramuli measures 100-200 mm long and 5 mm wide.
The cartilage-like stem of the plant, called a stolon, grows flat along the rock attached by fine outgrowths. Growing out from the stolon are five rows of photosynthetic ramuli, each of which tapers to a short, blunt, spinous tip.
Caulerpa is really bright green in colour. It is a very noticeable algae.
In Australia, this species of Caulerpa, occurs only in New South Wales.
Recent research reveals that it also occurs in South Africa. It is uncertain whether it is a recent immigrant from Africa, but many researchers state that it wasn't as abundant only as recent as 20 years ago. It was first recorded near Sydney in 1923. It appears to be taking over large areas and is crowding out other algae forms.
Caulerpa is found at low-tide levels along the edges of rock platforms and in gutters, on medium- to high-energy shores, down to 40 metres. It can be found near Cunjevoi at low-tide level.
There is evidence that this algae is a recent immigrant from South Africa. It appears to be taking over many habitats along the New South Wales rocky shores, so that it is now the most abundant algae to be found. It is so common that it may be reaching pest, or even plague proportions, and excluding other local species.
Another explanation for
this rapid take-over may be due to human pollution altering the habitat
so much that only this species can take advantage of the new conditions.
How can we test these hypotheses out ?
Bennett, I. (1987) W.J. Dakin's classic study: Australian Seashores. Angus & Robertson, Sydney.
Davey, K. (1998) A Photographic Guide to Seashore Life of Australia. p.22, New Holland, Sydney.
Edgar, G. J. (1997) Australian Marine Life: the plants and animals of temperate waters. p.37, Reed Books, Kew.