#asteriidae

A common starfish (Asterias rubens) washed ashore near the White Sea in Russia

This one only has 5 arms. Sometimes they have eight. One of New Zealand's larger seastars, but also found in Eastern and Southern Australia.

A wandering predator of molluscs including mussels and sea snails, found from intertidal areas down to 150m. They may be orange through dark red to brown, or light blue to grey. Adults may be 35cm across, but intertidal individuals are generally smaller with thicker armour.

Giant-spined starfish (Pisaster giganteus)

An ochre sea star (Pisaster ochraceus) in Seal Rock, Oregon, USA

A blue spiny starfish takes a bow. Scientists have discovered that the ‘arms’ of a starfish are actually extensions of their head. A biologist commented that one could think of the body of a starfish as ‘a disembodied head walking about the sea floor on its lips – the lips having sprouted a fringe of tube feet, co-opted from their original function of sorting food particles, to do the walking’ - Photograph: bennymarty/Getty Images

A large - 25cm across - predatory seastar that I found hurrying across the bottom of a tidepool just after sunset. It usually has 11 arms, but can have as few as 7 or as many as 14. This is one of the species that can reproduce asexually, by tearing themselves in half.

Cape Peron, Perth

Pisaster ochraceus

オーカースター アラスカからカリフォルニア半島にかけて生息。

Ochre star It is found from Alaska to Baja California.