Microcosmus squamiger

Thought to have originated in Australia, this species is now found worldwide and is a concerning pest in many places as it competes with native species. In SA, this small solitary ascidian can be found, often in great numbers, on exposed surfaces such as jetty pylons and rocky reef. Usually heavily encrusted, it has a warty and globular body, with short siphons. Its colouration can vary, from reddish-orange to almost cream. Its most distinctive feature is its siphons, which are striped brown and cream on the inside. This striped pattern does not extend far before it gives way to a solid or speckled white colouration. This species is difficult to identify, but the siphons have a greater number of stripes than those of similar species, such as Polyandrocarpa zorritensis, Styela plicata/canopus or Halocynthia dumosa.