Sea Star; Red

Petricia vernicina

The red sea star is in the Asteropseidae family which is distinguished by its soft, rubbery, smooth skin texture and large central disc in relation to the size of its arms.  They have large conspicuous balloon-like extensions covering the body, known as respiratory papulae.  These papulae are operated by the water vascular system, a characteristic of echinoderms, which allow gas exchange for respiration and excretion of waste.  Red sea stars are generally a bright orange to red colour, however colouration can vary greatly in this species from grey, white, orange, brown, red and purple.  Similarly to the mosaic sea star, the red sea star has large marginal plates extending around the outside of the body, these remain hidden by papulae and are generally only visible in dried specimens.  They have an arm radius of 9 centimetres, a maximum body width of 22 centimetres.

The red sea star is a temperate species occurring most commonly on moderately exposed reef , though also on sheltered and fully exposed reefs to depths of 60 metres.  It feeds on encrusting invertebrates, such as sponges, ascidians and bryozoans. The red sea star is one of the most common sea stars encountered off the Perth coastline, their distribution ranges from the Houtman Abrolhos Islands, WA around southern Australia and Tasmania, to Caloundra, Qld.

Other common names include:  Velvet sea star

Occurrence at the Busselton Jetty:

The red sea star is a striking bright red, allowing it to be easily seen in prominent positions from the underwater observatory.

Image by: S. Teede